Why do Women have breasts?

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Paps Anu, Ireland (If you look closely, someone put nipples on top.)

Well, there’s a clickbaity title if ever I wrote one.

Nevertheless, human breasts are strange. Sure, all females of the class mammalia are equipped with mammary glands for producing milk, but humans alone posses permanent, non-functional breasts.

Yes, non-functional: the breast tissue that develops during puberty and that you see on women all around you is primarily fat. Fat does not produce milk. Milk ducts produce milk. They are totally different things.

Like all other mammals, the milk-producing parts of the breasts only activate–make milk–immediately after a baby is born. At any other time, milk production is a useless waste of calories. And when mothers begin to lactate, breasts noticeably increase in size due to the sudden production of milk.

A woman’s normal breast size actually tells you nothing at all about her ability to make milk–if anything, the correlation is the opposite, with obese women (with correspondingly large breasts) having a more difficult time nursing and producing milk:

A number of factors associated with low milk supply have been identified, such as nipple pain, ineffective nursing, hormonal disorders, breast surgery, certain medications, and maternal obesity. …  Research into breast size and milk production shows that milk supply is not dependent on breast size, but rather on the amount of epithelial tissue contained in a breast that is capable of making milk …

However, in addition to baby attachment issues, accumulating evidence shows that a major factor preventing overweight and obese mothers to breastfeed is the inability of their breast epithelial cells to start producing copious amounts of milk after birth. This is often referred to as unsuccessful initiation of lactation. …

a recent study took advantage of breast epithelial cells non-invasively isolated from human milk. In these cells, certain genes are turned on, which enable the cells to gradually make milk as the breast matures during pregnancy, and then deliver it to the baby during breastfeeding.

The study reported a negative association between maternal BMI (body mass index), and the function of a gene that represents the milk-producing cells. This suggested that the breast epithelial tissue is not as mature and ready to make copious amounts of milk in mothers with higher BMI. Most likely, the large breasts of overweight or obese mothers contain more fat cells than milk-making cells, which can explain the low milk supply of many of these mothers.

Therefore, breast size does not necessarily translate to more milk-producing cells or higher ability to make milk.

More fat=less room for milk production.

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original source (colors have been changed.)

Interestingly, average cup size varies by country.  Of course the data may not be 100% accurate, and the lumping of everyone together at the national level obscures many smaller groups, like Siberians, but it otherwise still indicates some general trends that we can probably trust.

If breasts don’t actually make milk, then why on Earth do we have them? Why are women cursed with lumpy fat blobs hanging off their chests that have to be carefully smushed into specialized clothing just so we can run without them flopping around painfully?

And for that matter, why do we think they look nice?

One reasonable theory holds that breasts are really just front-butts. Our apish ancestors, like modern chimpanzees, most likely not copulate ad libitum like we do, but only when females were fertile. Female fertility among our chimpish relatives is signaled via a significant swelling and reddening of their rear ends, a clear signal in a species that wears no clothes and often walks on four limbs.

peter-paul-rubens-portrait-of-susanna-fourment-le-chapeau-de-paille
Le Chapeau, Peter Paul Rubens’s portrait of Susanna Fourmer

When humans began walking consistently on two legs, wearing clothes, and looking at each other’s faces, this obvious signal of female fertility was lost, but not our desire to look at rear-ends. So we simply transferred this desire to women’s fronts and selectively had more children with the women who piqued our interests by having more butt-shaped cleavage.

In support of this theory, many women go to fair lengths to increase the resemblance between their ample bosoms and an impressive behind; against this theory is the fact that no other bottom-obsessed species has accidentally evolved a front-butt.

I realized yesterday that there is an even simpler potential explanation: humans are just smart enough to be stupid.

Most of us know that breasts produce milk. Few of us really understand the mechanism of how they produce milk. I had to explain that fat lumps don’t produce milk at the beginning of this post because so few people actually understand this. Far more people think “Big breasts=lots of milk” than think “big breasts=lactation problems.” Humans have probably just been accidentally selecting for big breasts for millennia while trying to select for milk production.

Our breast obsession is cargo-cult lactation.

 

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Feel Something

My Name is Ruin, by Gary Numan

Me: In my zone, listening to music
Husband: Look at this dumb shit someone said on the internet
Me: What? Brains?

So far, everything I have listened to on this album is excellent.

By the way, Mongolia still isn’t sorry–The Hu, Yuve Yuve Yu

Mongolia is going to fuck your shit up and take your women, apparently.

Nirvana: Smells Like Teen Spirit

Guys, I have discovered the point of music. It’s sex.

Alice in Chains: Them Bones

In retrospect, I guess it’s not a surprise that a lot grunge musicians died of drugs or suicide.

Smashing Pumpkins: Bullet with Butterfly Wings

As long as you can still scream, you can still feel.

I don’t know if we can scream anymore.

Placebo–literally, “I please”–Sucker Love:

Their lead singer is a good example of a male playing up his effeminate qualities in order to get laid.
Husband: You can’t just say that without explanation.
Me: Have you seen the lead singer? I guarantee he gets tons of sex.
Husband: Is he gay?
Me: Whatever he’s into, he gets plenty of it.

There’s a lesson here for effeminate men thinking “Hey, would it be easier for me if I became a girl?”

No. It wouldn’t. Be you. Own who you are and find the people who are attracted to you.

AFI: Miss Murder

Gary Numan aside, it seems like the music scene has changed in fundamental ways over the past few decades. I don’t think there is anyone in the business today whose suicide would affect teens like Kurt Cobain’s, just because there is no one that widely loved. It’s not that society is more divided (though perhaps it is); we just don’t listen to music like we used to.

Of course popular music is still around, and still of varying (usually low) quality.

To hazard a guess, if music is really about reproducing, then the change in music is related to the decline in birth rates. A typical modern human mating ritual involves going to a club, listening to a band or some very loud recorded music, getting drunk, and meeting someone you’d like to have sex with. These clubs also provide a place for new bands to get started. But if fewer people go out, clubs close, people meet fewer other people, people are lonelier, birth rates drop, and new bands have a harder time getting noticed, and the industry changes.

On a final note:

This is why certain traits persist in the population.

Learning in Numbers

There is strength in numbers, but is there wisdom?

I’ve heard from multiple sources the claim that parenting, paradoxically, gets easier after the fourth child. There are several simple explanations for this phenomenon: people get more skilled at parenting after lots of practice; the older kids start helping out with the younger ones, etc.

But what if the phenomenon rests on something much more basic about human psychology–our desire to imitate others?

(Perhaps you don’t, dear reader. There are always exceptions.)

As Aristotle put it, man is a political animal–by which he meant that we are inherently social and prone to building communities (polities) together, not that we are inherently prone to arguing about who should govern North Carolina, though that may be political, too. In Aristotle’s words, a man who lives entirely alone is either a beast (living like an animal) or a god (able to fulfill all of his own needs without recourse to other humans.) Normal humans depend in many ways on other humans.

Compared to our pathetic ability to learn math (just look at most people’s SAT-math scores) and inability to read without direct instruction, humans learn socially-imparted skills like the ability to speak multiple languages, play games, assert dominance over each other, which clothes are fashionable, and how to crack a socially-appropriate joke with ease.

Social learning comes so naturally to people that we only notice it in cases of extreme deficit–like autism–or when parents protest that their children are becoming horribly corrupted by their peers.

So perhaps households with more than 4 children have hit a threshold beyond which social learning takes over and the younger children simply seem to “absorb” knowledge from their older siblings instead of having to be explicitly taught.

Consider learning to eat, a hopefully simple task. We are born with instincts to nurse, put random things in our mouths, and swallow. Preventing babies from eating random non-food objects is a bit of a problem for new parents. But learning things like “how to get this squishy food into your mouth with a spoon without also getting it everywhere else in the room” is much more complicated–and humans take food rituals to much more complicated heights than strained peas and carrots.

Parents of new children put a great deal of effort into teaching them to eat (something that ought to be an instinct.) Those with means puree fresh veggies, chop bits of meat, show a sudden interest in organics, and sit down to spoon every single last bit into their infants’ mouths. It is as if they are convinced that kids cannot learn to eat without at least as much instruction as a student learning to wield a welding torch. (And based on my own experience, they’re probably right.)

By contrast, parents of multiple children have–by necessity–relaxed. As a popular comic once depicted (though I can’t find it now,) feeding at this point becomes throwing Cheerios at the highchair as you run by.

Yet I’ve never seen any evidence that the younger children in large families are likely to be malnourished–they seem to catch the Cheerios on the fly and do just fine.

What if imitation is a strong factor in larger families, allowing infants and young children to learn skills like “how to eat” without needing direct parental instruction just by watching their older siblings? You might object that even infants in single parent households could learn to eat by imitating their parents (and they probably do,) but having more people around probably enforces the behavior more strongly, and having younger children around gives an example that is much more similar to the infant. We adults are massive compared to children, after all.

If basic learning of life skills proceeds more easily in an environment with more peers,(for infants or adults,) then what effects should we expect from our current trend toward extreme atomization?

I recently came across an essay about life in a trailer park vs sturdier housing:

To me, growing up in that trailer park meant playing until dark with neighborhood kids, building tree houses and snow forts. Listening out my bedroom window for the sound of my dad’s pickup truck leaving for work in the early morning. Riding my bike down the big hill at the top of the lot, avoiding potholes and feeling safe because there wasn’t much traffic and if I fell and skinned my knee, someone would come out on their front porch and ask if I was okay.

Some of the only happy memories I have of my childhood were from that time in my life, before my parents were thrust into insurmountable debt, before my mother was hospitalized, before I had to go live with my grandmother. Nana had a real house. She didn’t live in a trailer. But when she would scream at me or try to attack me as I squeezed by her and fled upstairs, I wished I had neighbors close by to hear her — to believe me, and to perhaps even help.

The most dysfunctional and unstable years of my life were spent in a real house, with four walls and a slanted roof — where fences went up between the houses so that no one ever had to feel responsible for what went on behind their neighbor’s front door.

This is more about atomization than learning, but still interesting. Is it good for humans to be so far apart? To live far from relatives, in houses with thick walls, as single children or single adults, working and commuting every day among strangers?

Certainly the downsides of being among relatives are well-documented. Many tribal societies have downright cruel customs directed at relatives, like sati or adult circumcision. But that doesn’t mean that the extreme opposite–total atomization–is perfect. Atomization carries other risks. Among them, staying indoors and not socializing with our neighbors may cause us to lose some of our social knowledge, our ability to learn how to exist together.

We might expect that physical atomization due to technological change (sturdier houses, more entertaining TV, comfier climate control systems,) could cause symptoms in people similar to those caused by medical deficits in social learning, like autism. A recent study on the subject found an interesting variation between the brains of normies and autists:

So great was the difference between the two groups that the researchers could identify whether a brain was autistic or neurotypical in 33 out of 34 of the participants—that’s 97% accuracy—just by looking at a certain fMRI activation pattern. “There was an area associated with the representation of self that did not activate in people with autism,” Just says. “When they thought about hugging or adoring or persuading or hating, they thought about it like somebody watching a play or reading a dictionary definition. They didn’t think of it as it applied to them.” This suggests that in autism, the representation of the self is altered, which researchers have known for many years, Just says.

This might explain the high rates of body dysmorphias in autism. It might also explain the high rates in society.

I remember another study which I read ages ago which found that people basically thought about “God” in the same parts of their brain where they thought about themselves. This explains why God tends to have the same morals as His believers. If autists have trouble imagining themselves, then they may also have trouble imagining God–and this might explain rising atheism rates.

Even our rising autism rates, though probably driven primarily by shifts in diagnostic fads, might be influenced by shrinking families and greater atomization, as kids with borderline conditions might show more severe symptoms if they are also more isolated.

On the other hand, social media is allowing people to come together and behave socially in new and ever larger groups.

For all their weaknesses, autists are probably better at normies at certain kinds of tasks, like abstract reasoning where you don’t want to think too much about yourself. I have long suspected that normies balk at philosophical dilemmas such as the trolley problem because they over-empathize with the subjects. Imagining themselves as one of the victims of the runaway trolley causes them distress, and distress causes them to attack the person causing them distress–the philosopher.

And so the citizens of Athens condemned Socrates to death.

But just as people can overcome their natural and very sensible fear of heights in order to work on skyscrapers, perhaps they can train themselves not to empathize with the subjects of trolley problems. Spending time on problems with no human subjects (such as mathematics or engineering) may also help people practice ways of approaching problems that don’t immediately resort to imagining themselves as the subject. On the converse, perhaps a bit of atomization (as seen historically in countries like Britain and France, and recently AFAIK in Japan,) helps equip people to think about difficult, non-human related mathematical or engineering problems.

Thoughts?

A theory of male and female Sociopathy pt 3

Note: this is just a theory, developed in reaction to recent conversations. 

From Twitter user FinchesofDarwin comes an interesting tale, about a polygynously-married woman in Guiana: 

Manwaiko had two wives, and each of these had a family of young children. … Between the two wives and their respective children little kindness seemed to exist. One evening, while the party were squatting on the ground, eating their supper… one of the wives, who with her children had been employed in cutting firewood, discovered, on her return, that the supper for herself and her family was not to be found, having been carried off by some animal through neglect or connivance of her rival. It could hardly be expected that she would sit down quietly without the evening meal for herself and her children… and she accordingly applied to Manwaiko for a share of his allowance, which was ample. He treated her request with contempt… She then commenced a furious torrent of abuse, during which he finished his meal with great composure, until, being irritated at his indifference, she at last told him that he was no “capitan,” no father, and no man. …  

Such stormy ebullitions of temper are rare in the Indian families, though, where polygamy is practiced, continual variance and ill-feeling are found. 

From The Indian Tribes of Guiana, their Condition and Habits, by Reverend Brett, 1868

As we were discussing Friday, one form of female sociopathy (at least relevant to this conversation) likely involves manipulating or coercing others into providing resources for her children. On Monday we discussed mental illness and its effects on fertility (generally it lowers fertility in men, but depression has little to no effect on women, neuroticism may enhance fertility, and sometimes the sisters of people with mental illnesses have slightly increased fertility, suggesting that low levels of certain traits may be beneficial.) 

Here is where I get 100% speculative, and to be frank, I don’t like saying negative things about women (since I am one,) but if men can be sociopaths, then women can, too–and conversely, the majority of men are not sociopaths, and neither are the majority of women. 

In the quoted passage, we see two common tropes: First, the evil stepmother, in the form of the wife who let wild animals make off with half of the family’s food. Second, the crazy bitch, who goes on a tirade questioning her husband’s manliness because he has failed to provide food for her children. 

In this case, only the first woman is truly sociopathic (she has harmed the other woman and her children,) but we can see how the second’s behavior could easily spill over into unreasonable demands. 

Female sociopathy–manipulating men out of their money–only works as an evolutionary strategy in an environment where men themselves vary in their trustworthiness and cannot be easily predicted. If the men in a society can be counted upon to always provide for their offspring, women have no need to try to manipulate them into doing so; if men in a society flat out refuse to do so, then there is no point to trying. Only in a situation where you can affect the amount of resources you get out of a man will there be any point to doing so.

Given the environmental constraints, sociopathic female behavior is likely to increase in reaction to an increase in sociopathic male behavior–that is, when women fear abandonment or an inability to care for their children.

This manipulation has two targets–first, the father of the child, whom the woman wishes to prevent from wandering off and having children with other women, or baring that, from giving them any resources. Second, should this fail, or the male be too violent for women and children to be near, the woman targets a new male to convince him to care for her, her children, and possibly beat the resources out of the old male. 

Since children actually do need to eat, and getting enough resources can be tough, society is generally fine with women doing what they need to provide for their families (unlike men doing whatever they need to maximize reproduction, which usually ends with the police informing you that no, you cannot go “Genghis Khan” on Manhattan.) 

But at times women really do go overboard, earning the title of “crazy ex.” Here’s part of one woman’s helpful list of why she went crazy:

1. He told me he loved me, then he left me. … I wasn’t going to make it easy for him to leave me. I promised myself I’d fight for my relationship because I loved him and he said he loved me. …
3. If you didn’t know, one of the quickest ways to drive a woman insane is to ignore her. … This was the most severe phase of crazy for me. I was infuriated that not only was I losing my relationship and wasn’t given a reason why, but I was being blatantly ignored by him too! …
4. He told me not to worry about his “friend,” and now he’s dating her.

Back before the invention of birth control, a woman who got dumped like this was most likely pregnant, if not already caring for several children. Abandonment was a big deal, and she had every reason not to just let her partner wander off and start impregnating new chicks. 

In our modern world, he made it clear that he didn’t want to be in a relationship anymore and left. 

Meanwhile: 

And a similar story on Quora

After my ex boyfriend broke up with me I went crazy… After he dumped me for the third time I felt used and devastated. I wanted an explanation and answers. He was a jerk to me. A cruel son of a bitch. I kept begging, calling, and begging. I never got a reply back. This went on for over 3 months. …

Third. Time. 

This isn’t the only kind of “crazy” I’ve seen around, though. 

An acquaintance recently recounted a story about an ex who actually ended up in the mental hospital for suicidal ideation. She listed him as her contact, something he was not exactly keen on, having already told her the relationship was over. 

Then there is the phenomenon of people actually claiming to be crazy, often with rather serious disorders that you would not normally think they would want to revealing to others. For example, I have seen several young women claim recently to have Multiple Personality Disorder–a condition that is not in the DSM and so you can no longer get diagnosed with it. Though you can get diagnosed with Disassociative Identity Disorder, this disorder is rare and quite controversial, and I would expect anyone with a real diagnosis to use the real name, just as few schizophrenics claim to have been diagnosed with dementia praecox. 

MPD is less of a real disorder and more of a fad spread by movies, TV, and unscrupulous shrinks, though many people who claim to have it are quite genuinely suffering. 

(I should emphasize that in most of these cases, the person in question is genuinely suffering.) 

Most of these cases–MPD, PTSD, etc–are supposedly triggered by traumatic experiences, such as childhood abuse or spousal abuse. (Oddly, being starved half to death in a POW camp doesn’t seem to trigger MPD.) And yet, despite the severity of these conditions, people I encounter seem to respond positively to these claims of mental illness–if anything, a claim of mental illness seems to get people more support. 

So I suggest a potential mechanism:

First, everyone of course has a pre-set range of responses/behaviors they can reasonably call up, but these ranges vary from person to person. For example, I will run faster if my kids are in danger than if I’m late for an appointment, but you may be faster than me even when you’re just jogging.

Second, an unstable, violent, or neglectful environmental triggers neuroticism, which in turn triggers mental instability. 

Third, mental instability attracts helpers, who try to “rescue” the woman from bad circumstances. 

Fourth, sometimes this goes completely overboard into trying to destroy an ex, convincing a new partner to harm the ex, spreading untrue rumors about the ex, etc. Alternatively, it goes overboard in the woman become unable to cope with life and needing psychiatric treatment/medication.

Since unstable environments trigger mental instability in the first place, sociopathic men are probably most likely to encounter sociopathic women, which makes the descriptions of female sociopathy automatically sound very questionable:

“My crazy ex told all of our friends I gave her gonorrhea!”

“Yeah, but that was after you stole $5,000 from her and broke two of her ribs.” 

This makes it difficult to collect objective information on the matter, and is why this post is very, very speculative. 

A theory of male and female Sociopathy pt 1

Note: this is just a theory, developed in reaction to recent conversations. 

Let us assume, first of all, that men and women have different optimal reproductive strategies, based on their different anatomy. In case you have not experienced birth yourself, it’s a difference of calories, time, and potential death. 

In the ancestral environment (before child support laws, abortion, birth control, or infant formula):

For men, the absolute minimal paternal investment in a child–immediate abandonment–involves a few minutes of effort and spoonful of semen. There are few dangers involved, except for the possibility of other males competing for the same female. A hypothetical man could, with very little strain or extra physical effort, father thousands of children–gay men regularly go through the physical motions of doing just that, and hardly seem exhausted by the effort.

For women, the absolute minimal parental investment is nine months of gestation followed by childbirth. This is calorically expensive, interferes with the mother’s ability to take care of her other children, and could kill her. A woman who tried to maximize her pregnancies from menarchy to menopause might produce 25 children. 

If a man abandons his children, there is a decent chance they will still survive, because they can be nursed by their mother; if a woman abandons her child, it is likely to die, because its father cannot lactate and so cannot feed it. 

In sum, for men, random procreative acts (ie, sex) are extremely low-cost and still have the potential to produce offspring. For women, random procreative acts are extremely costly. So men have an incentive to spread their sperm around and women have an incentive to be picky about when and with whom they reproduce.  

This is well known to, well, everyone. 

Now, obviously most men do not abandon their children (nor do most women.) It isn’t in their interest to do so. A man’s children are more likely to survive and do well in life if he invests in them. (In a few societies where paternity is really uncertain, men invest resources in their sisters’ children, who are at least related to them, rather than opting out altogether.) As far as I know, some amount of male input into their children or their sisters’ children is a human universal–the only variation is in how much. 

Men want to invest in their children because this helps their children succeed, but a few un-tended bastards here and there are not a major problem. Some of them might even survive. 

By contrast, women really don’t want to get saddled with bastards. 

We may define sociopathy, informally, as attempting to achieve evolutionary ends by means that harm others in society, eg, stealing. In this case, rape and child abandonment are sociopathic ways of increasing men’s reproductive success at the expense of other people. (Note that sociopathy doesn’t have a formal definition and I am using it here as a tool, not a real diagnosis. If someone has a better term, I’m happy to use it.)

This is, again, quite obvious–everyone knows that men are much more likely than women to be imprisoned for violent acts, rape included. Men are also more likely than women to try to skip out on their child support payments. 

Note that this “sociopathy” is not necessarily a mental illness, (a true illness ought to make a dent on one’s evolutionary success.) Genghis Khan raped a lot of women, and it turned out great for his genes. It is simply a reproductive strategy that harms other people. 

So what does female sociopathy look like? 

It can’t look like male sociopathy, because child abandonment decreases a woman’s fertility. For a woman, violence and abandonment would be signs of true mental defects. Rather, we want to look at ways women improve their chances of reproductive success at the expense of others. 

In other words, female sociopathy involves manipulating or coercing others into providing resources for her children. 

But it’s getting late; let’s continue with part 2 on Monday. (Wednesday is book club.)

Mysticism and Greater Male Variability

ctqda7fweae8tnbBuzzwords like “the male gaze” “objectification” “stereotype threat” “structural oppression” “white privilege” etc. are all really just re-hashings of the Evil Eye. We’ve shed the formal structure of religion but not the impulse for mystical thinking.

Today while debating with a friend about whether men or women have it better, it became plain that we were approaching the question from very different perspectives. He looked at men’s higher incomes and over-representation among CEOs and government officials and saw what I’ll call the mystical explanation: male oppression of women. I looked at the same data plus male over-representation among the homeless, mentally ill, suicides, and murder victims, and advocated the scientific explanation: greater male variability. 

What do I mean by mystical?

In primitive tribes, an accusation of witchcraft can quickly get you killed. What might inspire an accusation of witchcraft? A sick cow, a sudden death, a snake in a spot where it wasn’t yesterday, a drought, a flood, a twisted ankle–pretty much anything unexpected or unfortunate.

People understand cause and effect. Things happen because other things make them happen. But without a good scientific understanding of the world, the true causes of many events are unfindable, so people turn to mystical explanations. Why does it rain? Because a goddess is weeping. Why do droughts happen? Because someone forgot to make a sacrifice and angered the gods. Why do people get sick and die? Because other people cursed them.

If you’ve never encountered animist or mystical thought before, I recommend starting with some of my previous posts on the subject, which are thoroughly-researched and include lots of quotes from first-hand sources: Animism 1, 2, and 3; Aboriginal Witchcraft, more Australia 1, 2, and 3; mysticism and voodoo 1, 2, and 3. In this post I will be drawing on summaries of these and similar works.

A curse need not be deliberate. Simply being mad at someone or bearing them ill-will might be enough trigger the Evil Eye, curse them, and be forced by angry villagers to undo the curse–however the witchdoctor determines the curse must be undone. (This can be quite expensive.)

In animist thinking, things do not just happen. Things happen for reasons–usually malicious reasons.

In The Life and Adventure of William Buckley, 32 Years a Wanderer amongst the Aborigines, Buckley recounts: “They have an odd idea of death, for they do not suppose that any one dies from natural causes, but from human agencies: such as those to which I have alluded in previous pages of this narrative.”

The death of a companion via snakebite (probably a  common occurrence among people who walk barefoot in Australia) triggered a brutal “revenge” killing once it was determined who had cast the curse that motivated the snake:

“The cause of this sudden unprovoked cruelty was not, as usual, about the women, but because the man who had been killed by the bite of the snake belonged to the hostile tribe, and they believed my supposed brother-in-law carried about with him something that had occasioned his death. They have all sorts of fancies of this kind, and it is frequently the case, that they take a man’s kidneys out after death, tie them up in something, and carry them round the neck, as a sort of protection and valuable charm, for either good or evil.”

Buckley’s adoptive Aboriginal family, his sister and brother-in-law, who had been helping him since the tribe saved his life years ago, was killed in this incident.

“I should have been most brutally unfeeling, had I not suffered the deepest mental anguish from the loss of these poor people, who had all along been so kind and good to me. I am not ashamed to say, that for several hours my tears flowed in torrents, and, that for a long time I wept unceasingly. To them, as I have said before, I was as a living dead brother, whose presence and safety was their sole anxiety. Nothing could exceed the kindness these poor natives had shown me, and now they were dead, murdered by the band of savages I saw around me, apparently thirsting for more blood. Of all my sufferings in the wilderness, there was nothing equal to the agony I now endured.” …

“I returned to the scene of the brutal massacre; and finding the ashes and bones of my late friends, I scraped them up together, and covered them over with turf, burying them in the best manner I could, that being the only return I could make for their many kindnesses. I did so in great grief at the recollection of what they had done for me through so many years, and in all my dangers and troubles. ”

An account of Florence Young’s missionary work in the Solomon Islands (which are near Australia) recounts an identical justification for the cycle of violence on the Solomon Islands (which was quite threatening to Florence herself.) Every time someone died of any natural cause, their family went to the local witch doctor, who then used magic to determine who had used evil magic to kill the dead guy, and then the family would go and kill whomever the witch doctor indicated.

The advent of Christianity therefore caused a power struggle between the missionaries and the witch doctors, who were accustomed to being able to extort everyone and trick their followers into killing anyone who pissed them off. (See also Isaac Bacirongo’s account of the witch doctor who extorted his pre-pubescent sister as payment for a spell intended to kill Isaac’s wife–note: Isaac was not the one buying this spell; he likes his wife.)

So why do women make less money than men? Why are they underrepresented among CEOs and Governors and mathematicians? Something about the patriarchy and stereotype threat; something about men being evil.

Frankly, it sounds like men have the Evil Eye. A man thinks “Women are worse at math” and women suddenly become worse at math.

To be fair, my friend had only half the data, and when you have only half the data, the situation for men looks a lot better than the situation for women. But men aren’t only over-represented at the high ends of achievement–they’re also over-represented at the bottom. If patriarchy and stereotypes keep women from getting PhDs in math, why are little boys over-represented in special ed classes? Why are they more likely to be homeless, schizophrenic, commit suicide, or be murdered? Neither patriarchy nor male privilege can explain such phenomena.

Biology supplies us with a totally different explanation: greater male variability.

To review genetics, you have 23 pairs of chromosomes. Most of them are roughly X-shaped, except for the famous Y chromosome.

You have two chromosomes because you received one from each of your parents. Much of what the chromosomes do is redundant–for example, if you have blue eyes, then you received a gene for blue eyes from one parent and one from your other parent. One blue eye gene would be enough to give you blue eyes, but you have two.

Eye color isn’t terribly important, but things like how your immune system responds to threats or how your blood clots are. A rare mutation might make you significantly better or worse at these things, but the fact that you have two (or more) genes controlling each trait means that each very rare mutation tends to be paired with a more common version–lessening its effect.

There is, however, one big exception: the XY pair. Men don’t have a pair of Xs or a pair of Ys; they have one of each. If something is wrong on the X, the Y may have nothing to fix it, and vice versa.

The upshot is that if a man happens to get a gene that makes him extra tall, smart, conscientious, creative, charismatic, etc. somewhere on his X or Y chromosomes, he may not have a corresponding gene on the other chromosome to moderate its effects–and if he has a gene that makes him extra short, dumb, impulsive, dull, or anti-social, he is still unlikely to have a corresponding gene to dull the effect.

ci_generos
ASVAB scores: women in pink, men in blue.

Height is an uncontroversial example. Yes, the average man is taller than the average woman, but the spread of male heights is wider than the spread of female heights. More women are clustered around the average female height, while more men are both taller than the average man and shorter than the average man.

The graph to the right shows test scores from the Armed Services Vocational Aptitude Battery, but it shows the same basic idea: different means with women clustered more closely around average than men.

Whether the greater male variability hypothesis is true or not, it is an explanation that assumes no malice on anyone’s part. No one is maliciously forcing little boys into special ed, nor grown men into homelessness and suicide. The architecture of the XY and XX chromosome pairs is simply part of how humans are constructed.

But notice that you are much more likely to hear the theory that uses mysticism to blame people than the theory that doesn’t. One is tempted to think that some people are just inclined to assume that others are malicious–while ignoring other, more mundane explanations.

 

 

 

The Modular Mind

The other day I was walking through the garden when I looked down, saw one of these, leapt back, screamed loudly enough to notify the entire neighborhood:

(The one in my yard was insect free, however.)

After catching my breath, I wondered, “Is that a wasp nest or a beehive?” and crept back for a closer look. Wasp nest. I mentally paged through my knowledge of wasp nests: wasps abandon nests when they fall on the ground. This one was probably empty and safe to step past. I later tossed it onto the compost pile.

The interesting part of this incident wasn’t the nest, but my reaction. I jumped away from the thing before I had even consciously figured out what the nest was. Only once I was safe did I consciously think about the nest.

So I’ve been reading Gazzaniga’s Who’s in Charge? Free Will and the Science of the Brain. (I’m thinking of making this a Book Club pick; debating between this and Kurzweil’s How to Create a Mind: The Secrets of Human thought Revealed, which I have not read, but comes recommended. Feel free to vote for one, the other, or both.)

Gazzaniga discusses a problem faced by brains trying to evolve to be bigger and smarter: how do you get more neurons working without taking up an absurd amount of space connecting each and every neuron to every other neuron?

Imagine a brain with 5 connected neurons: each neuron requires 4 connections to talk to every other neuron. A 5 neuron brain would thus need space for 10 total connections.

The addition of a 6th neuron would require 5 new connections; a 7th neuron requires 6 new connections, etc. A fully connected brain of 100 neurons would require 99 connections per neuron, for a total of 4,950 connections.

The human brain has about 86 billion neurons.

Connecting all of your neurons might work fine if if you’re a sea squirt, with only 230 or so neurons, but it is going to fail hard if you’re trying to hook up 86 billion. The space required to hook up all of these neurons would be massively larger than the space you can actually maintain by eating.

So how does an organism evolving to be smarter deal with the connectivity demands of increasing brain size?

Human social lives suggest an answer: Up on the human scale, one person can, Dunbar estimates, have functional social relationships with about 150 other people, including an understanding of those people’s relationships with each other. 150 people (the “Dunbar number”) is therefore the amount of people who can reliably cooperate or form groups without requiring any top-down organization.

So how do humans survive in groups of a thousand, a million, or a billion (eg, China)? How do we build large-scale infrastructure projects requiring the work of thousands of people and used by millions, like interstate highways? By organization–that is, specialization.

In a small tribe of 150 people, almost everyone in the tribe can do most of the jobs necessary for the tribe’s survival, within the obvious limits of biology. Men and women are both primarily occupied with collecting food. Both prepare clothing and shelter; both can cook. There is some specialization of labor–obviously men can carry heavier loads; women can nurse children–but most people are generally competent at most jobs.

In a modern industrial economy, most people are completely incompetent at most jobs. I have a nice garden, but I don’t even know how to turn on a tractor, much less how to care for a cow. The average person does not know how to knit or sew, much less build a house, wire up the electricity and lay the plumbing. We attend school from 5 to 18 or 22 or 30 and end up less competent at surviving in our own societies than a cave man with no school was in his, not because school is terrible but because modern industrial society requires so much specialized knowledge to keep everything running that no one person can truly master even a tenth of it.

Specialization, not just of people but of organizations and institutions, like hospitals devoted to treating the sick, Walmarts devoted to selling goods, and Microsoft devoted to writing and selling computer software and hardware, lets society function without requiring that everyone learn to be a doctor, merchant, and computer expert.

Source

Similarly, brains expand their competence via specialization, not denser neural connections.

As UPI reports, Intelligence is correlated with fewer neural connections, not more, study finds:

The smartest people may boast more neurons than those of average intelligence, but their brains have fewer neural connections…

Neuroscientists in Germany recruited 259 participants, both men and women, to take IQ tests and have their brains imaged…

The research revealed a strong correlation between the number of dendrites in a person’s cerebral cortex and their intelligence. The smartest participants had fewer neural connections in their cerebral cortex.

Fewer neural connections overall allows different parts of the brain to specialize, increasing local competence.

All things are produced more plentifully and easily and of a better quality when one man does one thing that is natural to him and does it at the right time, and leaves other things. –Plato, The Republic

The brains of mice, as Gazzinga discusses, do not need to be highly specialized, because mice are not very smart and do not do many specialized activities. Human brains, by contrast, are highly specialized, as anyone who has ever had a stroke has discovered. (Henry Harpending of West Hunter, for example, once had a stroke while visiting Germany that knocked out the area of his brain responsible for reading, but since he couldn’t read German in the first place, he didn’t realize anything was wrong until several hours later.)

I read, about a decade ago, that male and female brains have different levels, and patterns, of internal connectivity. (Here and here are articles on the subject.) These differences in connectivity may allow men and women to excel at different skills, and since we humans are a social species that can communicate by talking, this allows us to take cognitive modality beyond the level of a single brain.

So modularity lets us learn (and do) more things, with the downside that sometimes knowledge is highly localized–that is, we have a lot of knowledge that we seem able to access only under specific circumstances, rather than use generally.

For example, I have long wondered at the phenomenon of people who can definitely do complicated math when asked to, but show no practical number sense in everyday life, like the folks from the Yale Philosophy department who are confused about why African Americans are under-represented in their major, even though Yale has an African American Studies department which attracts a disproportionate % of Yale’s African American students. The mathematical certainty that if any major in the whole school that attracts more African American students, then other majors will end up with fewer, has been lost on these otherwise bright minds.

Yalies are not the only folks who struggle to use the things they know. When asked to name a book–any book–ordinary people failed. Surely these people have heard of a book at some point in their lives–the Bible is pretty famous, as is Harry Potter. Even if you don’t like books, they were assigned in school, and your parents probably read The Cat in the Hat and Green Eggs and Ham to you when you were a kid. It is not that they do not have the knowledge as they cannot access it.

Teachers complain all the time that students–even very good ones–can memorize all of the information they need for a test, regurgitate it all perfectly, and then turn around and show no practical understanding of the information at all.

Richard Feynman wrote eloquently of his time teaching future science teachers in Brazil:

In regard to education in Brazil, I had a very interesting experience. I was teaching a group of students who would ultimately become teachers, since at that time there were not many opportunities in Brazil for a highly trained person in science. These students had already had many courses, and this was to be their most advanced course in electricity and magnetism – Maxwell’s equations, and so on. …

I discovered a very strange phenomenon: I could ask a question, which the students would answer immediately. But the next time I would ask the question – the same subject, and the same question, as far as I could tell – they couldn’t answer it at all! For instance, one time I was talking about polarized light, and I gave them all some strips of polaroid.

Polaroid passes only light whose electric vector is in a certain direction, so I explained how you could tell which way the light is polarized from whether the polaroid is dark or light.

We first took two strips of polaroid and rotated them until they let the most light through. From doing that we could tell that the two strips were now admitting light polarized in the same direction – what passed through one piece of polaroid could also pass through the other. But then I asked them how one could tell the absolute direction of polarization, for a single piece of polaroid.

They hadn’t any idea.

I knew this took a certain amount of ingenuity, so I gave them a hint: “Look at the light reflected from the bay outside.”

Nobody said anything.

Then I said, “Have you ever heard of Brewster’s Angle?”

“Yes, sir! Brewster’s Angle is the angle at which light reflected from a medium with an index of refraction is completely polarized.”

“And which way is the light polarized when it’s reflected?”

“The light is polarized perpendicular to the plane of reflection, sir.” Even now, I have to think about it; they knew it cold! They even knew the tangent of the angle equals the index!

I said, “Well?”

Still nothing. They had just told me that light reflected from a medium with an index, such as the bay outside, was polarized; they had even told me which way it was polarized.

I said, “Look at the bay outside, through the polaroid. Now turn the polaroid.”

“Ooh, it’s polarized!” they said.

After a lot of investigation, I finally figured out that the students had memorized everything, but they didn’t know what anything meant. When they heard “light that is reflected from a medium with an index,” they didn’t know that it meant a material such as water. They didn’t know that the “direction of the light” is the direction in which you see something when you’re looking at it, and so on. Everything was entirely memorized, yet nothing had been translated into meaningful words. So if I asked, “What is Brewster’s Angle?” I’m going into the computer with the right keywords. But if I say, “Look at the water,” nothing happens – they don’t have anything under “Look at the water”!

The students here are not dumb, and memorizing things is not bad–memorizing your times tables is very useful–but they have everything lodged in their “memorization module” and nothing in their “practical experience module.” (Note: I am not necessarily suggesting that thee exists a literal, physical spot in the brain where memorized and experienced knowledge reside, but that certain brain structures and networks lodge information in ways that make it easier or harder to access.)

People frequently make arguments that don’t make logical sense when you think them all the way through from start to finish, but do make sense if we assume that people are using specific brain modules for quick reasoning and don’t necessarily cross-check their results with each other. For example, when we are angry because someone has done something bad to us, we tend to snap at people who had nothing to do with it. Our brains are in “fight and punish mode” and latch on to the nearest person as the person who most likely committed the offense, even if we consciously know they weren’t involved.

Political discussions are often marred by folks running what ought to be logical arguments through status signaling, emotional, or tribal modules. The desire to see Bad People punished (a reasonable desire if we all lived in the same physical community with each other) interferes with a discussion of whether said punishment is actually useful, effective, or just. For example, a man who has been incorrectly convicted of the rape of a child will have a difficult time getting anyone to listen sympathetically to his case.

In the case of white South African victims of racially-motivated murder, the notion that their ancestors did wrong and therefore they deserve to be punished often overrides sympathy. As BBC notes, these killings tend to be particularly brutal (they often involve torture) and targeted, but the South African government doesn’t care:

According to one leading political activist, Mandla Nyaqela, this is the after-effect of the huge degree of selfishness and brutality which was shown towards the black population under apartheid. …

Virtually every week the press here report the murders of white farmers, though you will not hear much about it in the media outside South Africa.In South Africa you are twice as likely to be murdered if you are a white farmer than if you are a police officer – and the police here have a particularly dangerous life. The killings of farmers are often particularly brutal. …

Ernst Roets’s organisation has published the names of more than 2,000 people who have died over the last two decades. The government has so far been unwilling to make solving and preventing these murders a priority. …

There used to be 60,000 white farmers in South Africa. In 20 years that number has halved.

The Christian Science Monitor reports on the measures ordinary South Africans have to take in what was once a safe country to not become human shishkabobs, which you should pause and read, but is a bit of a tangent from our present discussion. The article ends with a mind-bending statement about a borrowed dog (dogs are also important for security):

My friends tell me the dog is fine around children, but is skittish around men, especially black men. The people at the dog pound told them it had probably been abused. As we walk past house after house, with barking dog after barking dog, I notice Lampo pays no attention. Instead, he’s watching the stream of housekeepers and gardeners heading home from work. They eye the dog nervously back.

Great, I think, I’m walking a racist dog.

Module one: Boy South Africa has a lot of crime. Better get a dog, cover my house with steel bars, and an extensive security system.

Module two: Associating black people with crime is racist, therefore my dog is racist for being wary of people who look like the person who abused it.

And while some people are obviously sympathetic to the plight of murdered people, “Cry me a river White South African Colonizers” is a very common reaction. (Never mind that the people committing crimes in South Africa today never lived under apartheid; they’ve lived in a black-run country for their entire lives.) Logically, white South Africans did not do anything to deserve being killed, and like the golden goose, killing the people who produce food will just trigger a repeat of Zimbabwe, but the modes of tribalism–“I do not care about these people because they are not mine and I want their stuff”–and punishment–“I read about a horrible thing someone did, so I want to punish everyone who looks like them”–trump logic.

Who dies–and how they die–significantly shapes our engagement with the news. Gun deaths via mass shootings get much more coverage and worry than ordinary homicides, even though ordinary homicides are far more common. homicides get more coverage and worry than suicides, even though suicides are far more common. The majority of gun deaths are actually suicides, but you’d never know that from listening to our national conversation about guns, simply because we are biased to worry far more about other people killng us than about ourselves.

Similarly, the death of one person via volcano receives about the same news coverage as 650 in a flood, 2,000 in a drought, or 40,000 in a famine. As the article notes:

Instead of considering the objective damage caused by natural disasters, networks tend to look for disasters that are “rife with drama”, as one New York Times article put it4—hurricanes, tornadoes, forest fires, earthquakes all make for splashy headlines and captivating visuals. Thanks to this selectivity, less “spectacular” but often times more deadly natural disasters tend to get passed over. Food shortages, for example, result in the most casualties and affect the most people per incident5 but their onset is more gradual than that of a volcanic explosion or sudden earthquake. … This bias for the spectacular is not only unfair and misleading, but also has the potential to misallocate attention and aid.

There are similar biases by continent, with disasters in Africa receiving less attention than disasters in Europe (this correlates with African disasters being more likely to be the slow-motion famines, epidemics and droughts that kill lots of people, and European disasters being splashier, though perhaps we’d consider famines “splashier” if they happened in Paris instead of Ethiopia.)

From Personality and Political Attitudes: “Conservatives are hard-working, organized, closed-minded, and emotionally stable. Liberals are lazy, disorganized, open-minded, and neurotic. Let’s see how the punditocracy spins that one.”

From a neuropolitical perspective, I suspect that patterns such as the Big Five personality traits correlating with particular political positions (“openness” with “liberalism,” for example, or “conscientiousness” with “conservativeness,”) is caused by patterns of brain activity that cause some people to depend more or less on particular brain modules for processing.

For example, conservatives process more of the world through the areas of their brain that are also used for processing disgust, (not one of “the five” but still an important psychological trait) which increases their fear of pathogens, disease vectors, and generally anything new or from the outside. Disgust can go so far as to process other people’s faces or body language as “disgusting” (eg, trans people) even when there is objectively nothing that presents an actual contamination or pathogenic risk involved.

Similarly, people who feel more guilt in one area of their life often feel guilt in others–eg, “White guilt was significantly associated with bulimia nervosa symptomatology.” The arrow of causation is unclear–guilt about eating might spill over into guilt about existing, or guilt about existing might cause guilt about eating, or people who generally feel guilty about everything could have both. Either way, these people are generally not logically reasoning, “Whites have done bad things, therefore I should starve myself.” (Should veganism be classified as a politically motivated eating disorder?)

I could continue forever–

Restrictions on medical research are biased toward preventing mentally salient incidents like thalidomide babies, but against the invisible cost of children who die from diseases that could have been cured had research not been prevented by regulations.

America has a large Somali community but not Congolese, (85,000 Somalis vs. 13,000 Congolese, of whom 10,000 hail from the DRC. Somalia has about 14 million people, the DRC has about 78.7 million people, so it’s not due to there being more Somalis in the world,) for no particular reason I’ve been able to discover, other than President Clinton once disastrously sent a few helicopters to intervene in the eternal Somali civil war and so the government decided that we now have a special obligation to take in Somalis.

–but that’s probably enough.

I have tried here to present a balanced account of different political biases, but I would like to end by noting that modular thinking, while it can lead to stupid decisions, exists for good reasons. If purely logical thinking were superior to modular, we’d probably be better at it. Still, cognitive biases exist and lead to a lot of stupid or sub-optimal results.

On Socialization

As a parent, I spend much of my day attempting to “socialize” my kids–“Don’t hit your brother! Stop jumping on the couch! For the umpteenth time, ‘yeah, right!’ is sarcasm.”

There are a lot of things that don’t come naturally to little kids. Many of them struggle to understand that these wiggly lines on paper can turn into words or that tiny, invisible things on their hands can make them sick.

“Yes, you have to brush your teeth and go to bed, no, I’m not explaining why again.”

And they definitely don’t understand why I won’t let them have ice cream for dinner.

“Don’t ride your bike down the hill and into the street like that! You could get hit by a car and DIE!”

Despite all of the effort I have devoted to transforming this wiggly bunch of feral children into respectable adults (someday, I hope,) I have never found myself concerned with the task of teaching them about gender. As a practical matter, whether the children behave like “girls” or “boys” makes little difference to the running of the household, because we have both–by contrast, whether the children put their dishes away after meals and do their homework without me having to threaten or cajole them makes a big difference.

Honestly, I can’t convince them not to pick their noses in public or that broccoli is tasty, but I’m supposed to somehow subtly convince them that they’ve got to play Minecraft because they’re boys (even while explicitly saying, “Hey, you’ve been playing that for two hours, go ride your bike,” or that they’re supposed to be walking doormats because they’re girls (even while saying, “Next time he pushes you, push him back!”)

And yet the boys still act like boys, the girls like girls–statistically speaking.

“Ah,” I hear some of you saying, “But you are just one parent! How do you know there aren’t legions of other parents who are out there doing everything they can to ensure that their sons succeed and daughters fail in life?”

This is, if you will excuse me, a very strange objection. What parent desires failure from their children?

Why do women love cupcakes?

Seriously.

One of my kids enjoys watching YouTube cooking videos, and they’re nearly 100% women making cakes.

Women’s magazines focus exclusively on 4 topics: men, fashion, diets, and cupcakes. You might think that diets and cupcakes are incompatible, but women’s magazines believe otherwise:

Picture 5 Picture 6 Picture 8

Just in case it’s not clear, that is not a watermellon. It is cake, cleverly disguised as a watermellon.

(YouTube has videos that show you how to make much better cake watermellons–for starters, you want red velvet cake for the middle, not just frosting…)

Picture 10 Picture 11Magazines specifically aimed at “people who want to make cakes” are also overwhelmingly feminine. Whether we’re talking wedding cakes or chocolate cravings, apple pastries or donuts, sweets and women just seem to go together.

If men’s magazines ever feature food, I bet they’re steak and BBQ. (*Image searches*)

Picture 19 Picture 18 Picture 14 Picture 16

 

 

 

 

Yup.

The meat-related articles do appear to be a little more gender-neutral than the cupcake-related articles–probably because men don’t tend to decorate their steaks with tiny baseball bats cut out of steak the way women like to decorate their cakes with tiny flowers made out of frosting.

It’s almost as if women have some kind of overwhelming craving for fats and sugars that men don’t really share.

I was talking with a friend recently about their workplace, where, “All of the women are on diets, but none of them can stay on their diets because they are all constantly eating at their workstations.” Further inquiries revealed that yes, they are eating sweets and pastries, not cashews and carrots, and that there is some kind of “office culture” of all of the women eating pastries together.

The irony here is pretty obvious.

Even many (most?) specialty “diet” foods are designed to still taste sweet. “Fat-free” yogurt is marketed as a health food even though it has as much sugar in it as a bowl of ice cream. Women are so attracted to the taste of sweet sodas, they drink disgusting Diet Coke. Dieting websites advise us that cake topped with fruit is “healthy.”

When men diet, they think “eat nothing but protein until ketosis kicks in” sounds like a great idea. When women diet, they want fat-free icecream.

I don’t think it is just “women lack willpower.” (Or at least, not willpower in the sense of something people have much control over.) Rather, I think that men and women actually have substantially different food cravings.

So do children, for that matter.

Throughout most of human history, from hunter-gatherers to agriculturalists, the vast majority of women have specialized in obtaining (gathering, tending, harvesting,) plants. (The only exceptions are societies where people don’t eat plants, like the Inuit and the Masai, and our modern society, where most of us aren’t involved in food production.) By contrast, men have specialized in hunting, raising, and butchering animals–not because they were trying to hog the protein or had some sexist ideas about food production, but because animals tend to be bigger and heavier than women can easily lift. Dragging home and butchering large game requires significant strength.

I am inventing a “Just So” story, of course. But it seems sensible enough that each gender evolved a tendency to crave the particular kinds of foods it was most adept at obtaining.

Exercise wears down muscles; protein is necessary to build them back up. Protein fuels active lifestyles, and active lifestyles, in turn, require protein. Our male ancestors’ most important activities were most likely heavy labor (eg, building huts, hauling firewood, butchering game,) and defending the tribe. Our female ancestors’ most important activities were giving birth and nursing children (we would not exist had they not, after all.) For these activities, women want to be fat. It’s not good enough to put on weight after you get pregnant, when the growing fetus is already dependent on its mother for nutrients. Far better for a woman to be plump before she gets pregnant (and to stay that way long after.)

Of course, this is “fat” by historical standards, not modern American standards.

I suspect, therefore, that women are naturally inclined to eat as much as possible of sweet foods in order to put on weight in preparation for pregnancy and lactation–only today, the average woman has 2 pregnancies instead of 12, and so instead of turning that extra weight into children and milk, it just builds up.

Obviously we are talking about a relatively small effect on food preferences, both because our ancestors could not afford to be too picky about what they ate, and because the genetic difference between men and women is slight–not like the difference between humans and lizards, say.

Interestingly, gender expression in humans appears to basically be female by default. If, by random chance, you are born with only one X chromosome, (instead of the normal XX or XY,) you can still survive. Sure, you’ll be short, you probably won’t menstruate, and you’ll likely have a variety of other issues, but you’ll be alive. By contrast, if you received only a Y chromosome from your parents and no accompanying X, you wouldn’t be here reading this post. You can’t survive with just a Y. Too many necessary proteins are encoded on the X.

Gender differences show up even in fetuses, but don’t become a huge deal until puberty, when the production of androgens and estrogens really cranks up.

Take muscle development: muscle development relies on the production of androgens (eg, testosterone.) Grownups produce more androgens than small children, and men produce more than women. Children can exercise and certainly children who do daily farm chores are stronger than children who sit on their butts watching TV all day, but children can’t do intense strength-training because they just don’t produce enough androgens to build big muscles. Women, likewise, produce fewer androgens, and so cannot build muscles at the same rate as men, though obviously they are stronger than children.

At puberty, boys begin producing the androgens that allow them to build muscles and become significantly stronger than girls.

Sans androgens, even XY people develop as female. (See Androgen Insensitivity Syndrome, in which people with XY chromosomes cannot absorb the androgens their bodies create, and so develop as female.) Children produce some androgens (obviously,) but not nearly as many as adults. Pre-pubescent boys, therefore, are more “feminine,” biologically, than post-pubescent men; puberty induces maleness.

All children seem pretty much obsessed with sweets, far more than adults. If allowed, they will happily eat cake until they vomit.

Even though food seems like a realm where evolution would heavily influence our tastes, it’s pretty obvious that culture has a huge effect. I doubt Jews have a natural aversion to pork or Hindus to beef. Whether you think chicken hearts are tasty or vomitous is almost entirely dependent on whether or not they are a common food in your culture.

But small children are blissfully less attuned to culture than grownups. Like little id machines, they spit out strained peas and throw them on the floor. They do not care about our notion that “vegetables are good for you.” This from someone who’ll eat bird poop if you let them.

The child’s affection for sweets, therefore, I suspect is completely natural and instinctual. Before the invention of refined sugars and modern food distribution systems, it probably kept them alive and healthy. Remember that the whole reason grownups try to eat more vegetables is that vegetables are low in calories. Grownups have larger stomachs and so can eat more than children, allowing them to extract adequate calories from low-calorie foods, but small children do not and cannot. In developing countries, children still have trouble getting enough calories despite abundant food in areas where that food is low-calorie plants, which they just cannot physically eat enough of. Children, therefore, are obsessed with high-calorie foods.

At puberty, this instinct changes for boys–orienting them more toward protein sources, which they are going to have to expend a lot of energy trying to haul back to their families for the rest of their lives, but stays basically unchanged in females.

ETA: I have found two more sources/items of relevance:

Calorie information effects on consumers’ food choices: Sources of observed gender heterogeneity, by Heiman and Lowengart:

When it comes to what we eat, men and women behave differently: Men consume more beef, eggs, and poultry; while women eat more fruits and vegetables and consume less fat than do men. … The gender differences in preferences for healthier foods begin in childhood. Previous literature has found that girls choose healthier food and are fonder of fruits and vegetables than are boys. Boys rated beef, processed meat, and eggs as more desirable than did girls. …

Sensory (taste) differences between the genders are the second most widely ventured explanation for the differences in food choices, although it is not clear that such genetic differences actually exist. While the popular media argue that females prefer sweetness and dislike bitterness, while males may enjoy bitterness, academic literature on this matter is less conclusive. The bitter taste receptor, gene TAS2R38, has been associated with the ability to taste PROP (6-n-propylthiouracil),
one source of genetic variation in PROP and PTC taste. Individuals who experience bitterness strongly are assumed to also experience sweetness strongly relative to those who experience PROP as only slightly bitter. While previous studies found that inherited taste-blindness to bitter compounds such as PROP may be a risk factor for obesity, this literature has been hotly disputed.

The distribution of perceived bitterness of PROP differs among women and men, as does the correlation between genetic taste measures and acceptance of sweetness. A higher percentage of women are PROP and PTC tasters, sensing bitterness above threshold. It has been suggested that women are more likely to be supertasters, or those who taste with far greater intensity than average.

(I have removed the in-line citations for ease of reading; please refer to the original if you want them.)

Also:

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Well, I don’t remember where this graph came from, but it looks like my intuitions were pretty good. males and females both have very low levels of testosterone during childhood, and duing puberty their levels become radically different.

I read a book and it’s Friday: Homicide, by Daly and Wilson

Today’s selection, Homicide, is ev psych with a side of anthropology; I am excerpting the chapter on people-who-murder-children. (You are officially forewarned.)

Way back in middle school, I happened across (I forget how) my first university-level textbook, on historical European families and family law. I got through the chapter on infanticide before giving up, horrified that enough Germans were smushing their infants under mattresses or tossing them into the family hearth that the Holy Roman Empire needed to be laws specifically on the subject.

It was a disillusioning moment.

Daly and Wilson’s Homicide, 1988, contributes some (slightly) more recent data to the subject, (though of course it would be nice to have even more recent data.

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(I think some of the oddities in # of incidents per year may be due to ages being estimated when the child’s true age isn’t known, eg, “headless torso of a boy about 6 years old found floating in the Thames.”)

We begin with a conversation on the subject of which child parents would favor in an emergency:

If parental motives are such as to promote the parent’s own fitness, then we should expect that parents will often be inclined to act so that neither sibling’s interests prevail completely. Typically, parental imposition of equity will involve supporting the younger, weaker competitor, even when the parent would favor the older if forced to choose between the two. It is this latter sort of situation–“Which do you save when one must be sacrificed?”–in which parents’ differential valuation of their children really comes to the fore. Recall that there were 11 societies in the ethnographic review of Chapter 3 for which it was reported that a newborn might be killed if the birth interval were too short or the brood too numerous. It should come as no surprise that there were no societies in which the prescribed solution to such a dilemma was said to be the death of an older child. … this reaction merely illustrates that one takes for granted the phenomenon under discussion, namely the gradual deepening of parental commitment and love.

*Thinks about question for a while* *flails* “BUT MY CHILDREN ARE ALL WONDERFUL HOW COULD I CHOSE?” *flails some more*

That said, I think there’s an alternative possibility besides just affection growing over time: the eldest child has already proven their ability to survive; an infant has not. The harsher the conditions of life (and thus, the more likelihood of actually facing a real situation in which you genuinely don’t have enough food for all of your children,) the higher the infant mortality rate. The eldest children have already run the infant mortality gauntlet and so are reasonably likely to make it to adulthood; the infants still stand a high chance of dying. Sacrificing the child you know is healthy and strong for the one with a high chance of dying is just stupid.

Whereas infant mortality is not one of my personal concerns.

Figure 4.4 shows that the risk of parental homicide is indeed a declining function of the child’s age. As we wold anticipate, the most dramatic decrease occurs between infants and 1-year-old children. One reason for expecting this is that the lion’s share of the prepubertal increase in reproductive value in natural environments occurs within the first year.

(I think “prepubertal increase in reproductive value” means “decreased likelihood of dying.”)

Moreover, if parental disinclination reflects any sort of assessment of the child’s quality or the mother’s situation, then an evolved assessment mechanisms should be such as to terminate any hopeless reproductive episode as early as possible, rather than to squander parental effort in an enterprise that will eventually be abandoned. … Mothers killed 61 in the first 6 months compared to just 27 in the second 6 months. For fathers, the corresponding numbers are 24 vs. 14. [See figure 4.4] … This pattern of victimization contrasts dramatically with the risk of homicide at the hands of nonrelatives (Figure 4.5)…

I would like to propose an alternative possibility: just as a child who attempts to drive a car is much more likely to crash immediately than to successfully navigate onto the highway and then crash, so a murderous person who gets their hands onto a child is more likely to kill it immediately than to wait a few years.

A similar mechanism may be at play in the apparent increase and then decrease in homicides of children by nonrelatives during toddlerhood. Without knowing anything about these cases, I can only speculate, but 1-4 are the ages when children are most commonly put into daycares or left with sitters while their moms return to work. The homicidally-minded among these caretakers, then, are likely to kill their charges sooner rather than later. (School-aged children, by contrast, are both better at running away from attackers and highly unlikely to be killed by their teachers.)

Teenagers are highly conflictual creatures, and the rate at which nonrelatives kill them explodes after puberty. When we consider the conspicuous, tempestuous conflicts that occur between teenagers and their parents–conflicts that apparently dwarf those of the preadolescent period–it is all the more remarkable that the risk of parental homicide continues its relentless decline to near zero.

… When mothers killed infants, the victims had been born to them at a mean age of 22.7 years, whereas older victims had been born at a mean maternal age of 24.5. Thi is a significant difference, but both means are signficantly below the 25.8 year that was the average age of all new Candian mothers during the same period, accoding to Cadian Vital Statistics.

In other words, impulsive fuckups who get accidentally pregnant are likely to be violent impulsive fuckups.

We find a similar result with respect to marital status: Mothers who killed older children are again intermediate between infanticidal women and the population-at-large. Whereas 51% of mothers committing infanticide were unmarried, the same was true of just 34% of those killing older children. This is still substantially above the 12% of Canadian births in which the new mother was unmarried …

Killing of an older child is often associated with maternal depression. Of the 95 mothers who killed a child beynd its infancy, 15.8% also committed suicide. … By contrast, only 2 of 88 infanticidal mothers committed suicide (and even this meager 2.3% probably overestimates the assocation of infanticide with suicide, since infanticides are the only category of homicides in which a significant incidence of undetected cases is likely.) … one of thee 2 killed three older children as well.

Anyone else thinking of Andrea Yates and her idiot husband?

In the Canadian data, it is also noteworthy that 35% of maternal infanticides were attributed by the investigating police force … [as] “mentally ill or mentally retarded (insane),” verses 58% of maternal homicides of older children. Here and elsewhere, it seems that the sots of cases that are simultaneously rare and seemingly contrary to the actor’s interests–in both the Darwinian and the commonsense meaning of interest–also happen t be the sorts of cases most likely to be attributed to some sort of mental incompetence. … We identify as mad those people who lack a species-typical nepotistic perception of their interests or who no longer care to pursue them. …

Violent people go ahead and kill their kids; people who go crazy later kill theirs later.

We do at least know the ages of the 38 men who killed heir infant children: the mean was 26.3 years. Moreover, we know that fathers averaged 4 years older than mothers for that substantial majority of Canadian births that occurred within marriages… . Since the mean age for all new Canadian mothers during the relevant period… was 25.8, it seems clear that infanticidal fathers are indeed relatively young. And as was the case with mothers, infanticidal fathers were significantly younger than those fathers who killed older offspring. (mean age at the victim’s birth = 29.2 years). …

As with mothers, fathers who killed older children killed themselves as well significantly more often (43.6% of 101) than did those who killed their infant children (10.5% of 38). Also like mothers is the fact that those infanticidal fathers who did commit suicide were significantly older (mean age = 30.5 years) than those who did not (mean = 25.8). Likewise, the paternal age at which older victims had been born was also significantly greater for suicidal (mean = 31.1 years; N = 71) than for nonsuicidal (mean =27.5; N = 67) homicidal fathers. And men who killed their older children were a little more likely to be deemed mentally incompetent (20.8%) than those who killed their infants (15.8%). …

Fathers, however, were significantly less likely to commit suicide after killing an adult offspring (19% of 21 men) than a child (50% of 80 men.) … 20 of the 22 adult victims of their father were sons… three of the four adult victims of mothers were daughters. … There is no hint of such a same-ex bias in the killings of either infants… or older children. …

An infrequent but regular variety of homicide is that in which a man destroys his wife and children. A corresponding act of familicide by the wife is almost unheard of. …

No big surprises in this section.

Perhaps the most obvious prediction from a Darwinian view of parental motives is this: Substitute parents will generally tend to care less profoundly for their children than natural parents, with the result that children reared by people other than their natural parents will be more often exploited and otherwise at risk. Parental investment is a precious resource, and selection must favor those parental psyches that do not squander it on nonrelatives.

Disclaimer: obviously there are good stepparents who care deeply for their stepchilden. I’ve known quite a few. But I’ve also met some horrible stepparents. Given the inherent vulnerability of children, I find distasteful our society’s pushing of stepparenting as normal without cautions against its dangers. In most cases, remarriage seems to be undertaken to satisfy the parent, not the  child.

In an interview study of stepparents in Cleveland, Ohio, for example–a study of predominantly middle-class group suffering no particular distress or dysfunction–Loise Duberman (1975) found that only 53% of stepfathers and 25% of stepmothers could claim to have “parental feeling” toward their stepchildren, and still fewer to “love” them.

Some of this may be influenced by the kinds of people who are likely to become stepparents–people with strong family instincts probably have better luck getting married to people like themselves and staying that way than people who are bad at relationships.

In an observational study of Trinidadian villagers, Mark Flinn (1988) found that stepfathers interacted less with “their” children than did natural fathers; that interactions were more likely to be aggressive within steprelationships than within the corresponding natural relationships; and that stepchildren left home at an earlier age.

Pop psychology and how-to manuals for stepfamilies have become a growth industry. Serious study of “reconstituted” families is also burgeoning. Virtually all of this literature is dominated by a single theme: coping with the antagonisms…

Here the authors stops to differentiate between between stepparenting and adoption, which they suspect is more functional due to adoptive parents actually wanting to be parents in the first place. However,

such children have sometimes been found to suffer when natural children are subsequently born to the adopting couple, a result that has led some professionals to counsel against adoption by childless couples until infertility is definitely established. …

Continuing on with stepparents:

The negative characterization of stepparents is by no means peculiar to our culture. … From Eskimos to Indonesians, through dozens of tales, the stepparent is the villain of every piece. … We have already encountered the Tikopia or Yanomamo husband who demands the death of his new wife’s prior children. Other solutions have included leaving the children with postmenopausal matrilineal relatives, and the levirate, a wide-spread custom by which a widow and her children are inherited by the dead man’s brother or other near relative. …

Social scientists have turned this scenario on its head. The difficulties attending steprelationships–insofar as they are acknowledged at all–are presumed to be caused by the “myth of the cruel stepparent” and the child’s fears.

See: Freud.

Why this bizarre counterintuitive view is the conventional wisdom would be  a topic for a longer book than this; suffice to say that the answer surely has more to do with ideology than with evidence. In any event, social scientists have staunchly ignored the question of the factual basis for the negative “stereotyping” of stepparents.

Under Freud’s logic, all sorts of people who’d been genuinely hurt by others were summarily dismissed, told that they were the ones who actually harbored ill-will against others and were just “projecting” their emotions onto their desired victims.

Freudianism is a crock of shit, but in this case, it helped social “reformers” (who of course don’t believe in silly ideas like evolution) discredit people’s perfectly reasonable fears in order to push the notion that “family” doesn’t need to follow traditional (ie, biological) forms, but can be reinvented in all sorts of novel ways.

So are children at risk in stepparent homes in contemporary North America? [see Figures 4.7 and 4.8.] … There is … no appreciable statistical confounding between steprelationships and poverty in North America. … Stepparenthood per se remains the single most powerful risk factor for child abuse that has yet been identified. (here and throughout this discussion “stepparents” include both legal and common-law spouses of the natural parent.) …

Speaking of Figures 4.7 and 4.8, I must say that the kinds of people who get divorced (or were never married) and remarried within a year of their kid’s birth are likely to be unstable people who tend to pick particularly bad partners, and the kinds of people willing to enter into a relationship with someone who has a newborn is also likely to be, well, unusual. Apparently homicidal.

By contrast, the people who are willing to marry someone who already has, say, a ten year old, may be relatively normal folks.

Just how great an elevation of risk are we talking about? Our efforts to answer that question have been bedeviled by a lack of good information in the living arrangements of children in the general population. … there are no official statistics [as of when this was written] on the numbers of children of each age who live in each household type. There is no question that the 43% of murdered American child abuse victims who dwelt with substitute parents is far more than would be expected by chance, but estimates of that expected percentage can only be derived from surveys that were designed to answer other questions. For a random sample of American children in 1976, … the best available national survey… indicates that only about 1% or fewer would be expected to have dwelt with a substitute parent. An American child living with one or more substitute parents in 1976 was therefore approximately 100 times as likely to be fatally abused as a child living with natural parents only…

Results for Canada are similar. In Hamilton, Ontario in 1983, for example, 16% of child abuse victims under 5 years of age lived with a natural parent and a stepparent… Since small children very rarely have stepparents–less than 1% of preschoolers in Hamilton in 1983, for example–that 16% represents forty times the abuse rate for children of the same age living with natural parents. … 147 Canadian children between the ages of 1 and 4 were killed by someone in loco parentis between 1974 and 1983; 37 of those children (25.2%) were the victims of their stepparents, and another 5 (3.4%) were killed by unrelated foster parents.

…The survey shows, for example, that 0.4% of 2,852 Canadian children, aged 1-4 in 1984, lived with a stepparent. … For the youngest age group in Figure 4.9, those 2 years of age and younger, the risk from a stepparent is approximately 70 times that from a natural parent (even though the later category includes all infanticides by natural mothers.)

Now we need updated data. I wonder if abortion has had any effect on the rates of infanticide and if increased public acceptance of stepfamilies has led to more abused children or higher quality people being willing to become stepparents.