Is Genius Fragile?

One of the subjects people care most about in ev psych and related disciplines is intelligence. Teachers would love it if all of their students suddenly began scoring in the 90th %; so would parents, of course. Tons of psychological studies have been done on subjects like “Do people score better on tests after thinking about famous scientists,” (without finding much useful,) not to mention millions of dollars spent on education reform without, as far as I can tell, much real change in school performances.

Since “IQ”–our best attempt at measuring and quantifying intelligence–appears to be at least 50% genetic, genes are a good spot to look when attempting to unravel the mystery of genius.

One of my theories on the subject is that if there are two kinds of dumb, perhaps there are two kinds of smart. Obviously dropping someone on their head is probably not going to result in genius, but perhaps there are some people who are smart due to having the good luck to have a variety of genes that generally code for things leading to high IQ, while other people are smart because they have a few particular genes or mutations. The folks with the generally IQ-boosting all-around genes are people who come from a background of parents and extended families with similar IQs to themselves, but folks with rare, particular, or novel mutations/genes would likely stand out even from their families. Such genes might have deleterious side effects or only confer genius in one or two particular arenas, resulting in, say, the stereotypical absent-minded professor or idiot savants.

If genius is fragile–my definition of fragile, not necessarily anyone else’s–then it is easily damaged; the difference between high-IQ and low-IQ in a particular population will be related to the possession of deleterious mutations that damage IQ. If IQ is not fragile–that is, if it is robust–then we would find rare, beneficial genes that boost IQ.

Environmentally, it is already obvious that genius is fragile–that is, it is much easier to drop someone one their head and subtract 40 IQ points than to find any intervention that will reliably add 40 points, but this does not necessarily preclude a variety of interesting genetic findings.

Perhaps I am thinking about this all wrong, but that’s the structure I’ve got worked out so far.

Anyway, so people have been searching for genes linked to IQ. Will they find specific IQ-boosting genes that highly intelligent people have, but dump people don’t? Or will they find specific IQ-damaging genes that dumb people have but intelligent people don’t? (Or maybe a combination of both?)

So, Neuroscience News recently covered a study published in Molecular Psychology that looked at genetic differences between highly intelligent people and the general population.

Now, I’m going to have to stop and point out a potential design flaw, at least according to the article:

“Published today in Molecular Psychiatry, the King’s College London study selected 1,400 high-intelligence individuals from the Duke University Talent Identification Program. Representing the top 0.03 per cent of the ‘intelligence distribution’, these individuals have an IQ of 170 or more – substantially higher than that of Nobel Prize winners, who have an average IQ of around 145.”

Duke TIP is aimed at middle schoolers, based largely on their elementary school test scores Anything that starts out by comparing the IQs of elementary school kids to people who’ve already won Nobel Prizes may not be saying much.

Second, I’d just like to note that while the article is unclear, they are probably not claiming that all Duke TIP participants have IQs over 170, since they don’t–Duke TIP’s own website states that they only require IQ scores over 125. Rather, I suspect they used the test scores submitted to the TIP program to select students with IQs over 170. If some confusion has occurred and they actually used people with 125s, well, results may not be as claimed.

Quick rough calculations indicate that 1,400 people in the top 0.03% is not an unreasonable number, since it would only require 4.667 million people, and there are about 4 million kids per grade level in the US, TIP takes from multiple grades, and they could have used multiple years’ worth of participants. But I don’t know how many kids TIP takes each year.

Anyway, results:

“The study focused, for the first time, on rare, functional SNPs – rare because previous research had only considered common SNPs and functional because these are SNPs that are likely to cause differences in the creation of proteins.

“The researchers did not find any individual protein-altering SNPs that met strict criteria for differences between the high-intelligence group and the control group. However, for SNPs that showed some difference between the groups, the rare allele was less frequently observed in the high intelligence group. This observation is consistent with research indicating that rare functional alleles are more often detrimental than beneficial to intelligence. …

‘Rare functional alleles do not account for much on their own but in combination, their impact is significant.

‘Our research shows that there are not genes for genius. However, to have super-high intelligence you need to have many of the positive alleles and importantly few of the negative rare effects, such as the rare functional alleles identified in our study.’

Or as the abstract puts it:

We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence.* Moreover, no significant associations were found for multiple rare alleles within individual genes. However, analyses using genome-wide similarity between unrelated individuals (genome-wide complex trait analysis) indicate that the genotyped functional protein-altering variation yields a heritability estimate of 17.4% (s.e. 1.7%) based on a liability model. In addition, investigation of nominally significant associations revealed fewer rare alleles associated with extremely high intelligence than would be expected under the null hypothesis. This observation is consistent with the hypothesis that rare functional alleles are more frequently detrimental than beneficial to intelligence.

*What does “and within the entire distribution of intelligence” mean in this sentence?

To be honest, I’m not sure about the interpretation that only genetic differences between high IQ and low IQ people is that the low-IQ have more deleterious mutations and the high-IQ don’t. For starters, we observe ethnic variation in IQ scores, and I find it difficult to believe that vast swathes of the planet, some of which have very different marriage patterns, have abnormally high levels of deleterious, fitness-reducing mutations that other swathes of the planet don’t.

I certainly can believe, though, that there are deleterious mutations that reduce IQ.

What do you guys think?

 

 

 

Women in Combat

The US Marines Tested Mixed-Gender Squads Against all Male ones, and the Results are Pretty Bleak

I will be writing a full post about this soon, but since I already have a month+ backlog, it’s going to be a while before it shows up here. Nevertheless, I think this is an important enough study that I want to bring your attention to it now. A few quotes:

“All branches of the military are facing a January 1, 2016, deadline to open all combat roles to women. …

“All-male squads, teams and crews and gender-integrated squads, teams, and crews had a noticeable difference in their performance of the basic combat tasks of negotiating obstacles and evacuating casualties. For example, when negotiating the wall obstacle, male Marines threw their packs to the top of the wall, whereas female Marines required regular assistance in getting their packs to the top. During casualty evacuation assessments, there were notable differences in execution times between all-male and gender-integrated groups, except in the case where teams conducted a casualty evacuation as a one-Marine fireman’s carry of another (in which case it was most often a male Marine who “evacuated” the casualty.)

“The report also says that female Marines had higher rates of injury throughout the experiment. …

“A military unit at maximum combat effectiveness is a military unit least likely to suffer casualties. Winning in war is often only a matter of inches, and unnecessary distraction or any dilution of the combat effectiveness puts the mission and lives in jeopardy. Risking the lives of a military unit in combat to provide career opportunities or accommodate the personal desires or interests of an individual, or group of individuals, is more than bad military judgment. It is morally wrong.”

The Insidious Approach of Death

A friend recently attended their 20th highschool reunion, the sort of event that makes one feel very old. Worse, three of their classmates have already died.

I thought that sounded way statistically unlikely, especially given the group’s demographics, but I ran the numbers, and it turns out that it’s only a little unlikely. Given the small N, we’re probably talking about random chance making the class unlucky rather than a particular propensity for death, but it’s unfortunate either way.

Highschool reunions are also a great (by which I mean depressing) opportunity to see who has aged the most. Some classmates look hardly older than the last time you saw them, while others look like they got hit by a semi full of old. Hopefully not you, of course.

In “Quantification of biological aging in young adults,” Belsky et al confirm what I’ve long suspected: that different people age at radically different rates, not just emotionally/mentally, but also biologically.

From the abstract: “We studied aging in 954 young humans, the Dunedin Study birth cohort, tracking multiple biomarkers across three time points spanning their third and fourth decades of life. We developed and validated two methods by which aging can be measured in young adults, one cross-sectional and one longitudinal. Our longitudinal measure allows quantification of the pace of coordinated physiological deterioration across multiple organ systems (e.g., pulmonary, periodontal, cardiovascular, renal, hepatic, and immune function). We applied these methods to assess biological aging in young humans who had not yet developed age-related diseases. Young individuals of the same chronological age varied in their “biological aging” (declining integrity of multiple organ systems). Already, before midlife, individuals who were aging more rapidly were less physically able, showed cognitive decline and brain aging, self-reported worse health, and looked older.” (bold mine.)

” We scaled the Pace of Aging so that the central tendency in the cohort indicates 1 y of physiological change for every one chronological year. On this scale, cohort members ranged in their Pace of Aging from near 0 y of physiological change per chronological year to nearly 3 y of physiological change per chronological year.”

“Study members with advanced Biological Age performed less well on objective tests of
physical functioning at age 38 than biologically younger peers (Fig. 5). They had more difficulty with balance and motor tests (for unipedal stance test of balance, r = −0.22, P < 0.001; for grooved pegboard test of fine motor coordination, r = −0.13, P < 0.001), and they were not as strong (grip strength test, r = −0.19, P < 0.001).”

“Study members with older Biological Ages had poorer cognitive functioning at midlife (r = −0.17, P < 0.001). Moreover, this difference in cognitive functioning reflected actual cognitive decline over the
years. When we compared age-38 IQ test scores to baseline test scores from childhood, study members with older Biological Age showed a decline in cognitive performance net of their baseline
level (r = −0.09, P = 0.010).”

“Neurologists have also begun to use high-resolution 2D photographs of the retina to evaluate age-related loss of integrity of blood vessels within the brain. Retinal and cerebral small vessels
share embryological origin and physiological features, making retinal vasculature a noninvasive indicator of the state of the brain’s microvasculature (32). Retinal microvascular abnormalities are associated with age-related brain pathology, including stroke and dementia (33–35) … study members with advanced Biological Age had older retinal vessels (narrower arterioles, r = −0.20, P < 0.001; wider venules, r = 0.17, P < 0.001).”

“… these biologically older study members were perceived to be older by independent observers.”

“Based on Pace of Aging analysis, we estimate that roughly 1/2 of the difference in Biological Age
observed at chronological age 38 had accumulated over the past 12 y.”

“… our analysis was limited to a single cohort, and one that lacked ethnic minority populations. Replication in other cohorts is needed, in particular in samples including sufficient numbers of ethnic minority individuals to test the “weathering hypothesis” that the stresses of ethnic minority status accelerate aging.”

“Three Dunedin Study members had Pace of Aging less than zero, appearing to grow physiologically younger during their thirties.”

While I suspect measurement error is at play, I’d still like to know what those guys did.

Conservatives and Liberals Assume Everyone Else is Like Themselves

Conservatives are well-known for their “pull yourself up by your bootlaces” ideology, and liberals have made whole careers out of claiming that conservatives are hypocrites who got a hand up  in their own lives, but want to deny that same help to everyone else. Conservatives, of course, claim that they got where they did by dint of sheer hard work and willpower.

So which is it? Are conservatives jut liars who want to keep all of the goodies for themselves? Or do they practice what they preach? And what about liberals? How hard are they trying to get ahead?

A recent article in the LA Times describes a study on willpower/self control:

“In a series of three studies with more than 300 participants, the authors found that people who identify as conservative perform better on tests of self-control than those who identify as liberal regardless of race, socioeconomic status and gender.”

What about age? (I suppose we can assume they probably controlled for age.)

They tested self control by asking volunteers to take the Stroop Test (reading words like “red” and “blue” printed in ink that’s a different color.) Accurately reading the cards without saying the color of the ink requires self-control and impulse-suppression, and conservatives tended to do better on the test than liberals.

They also found that conservatives are better at dieting.

In other words, people who themselves have a lot of self-control expect everyone else to have just as much self-control as they have.

In general, I find that people tend to assume that everyone else works the same way they do–for example, that criminals “know right from wrong,” in the same way as non-criminals, but for some reason chose to commit crimes.

Likewise, it appears that people who don’t have a lot of willpower assume that everyone else also doesn’t have a lot of willpower–and that conservatives are therefore lying when they say they hauled themselves up via bootstraps. (It must be some other, magical force at play.)

I am reminded here of a conversation I had with a liberal acquaintance over the Mike Brown case. (I feel compelled to note, here, that I don’t talk to this person anymore because I decided they have very bad judgment in the company they keep. That was a tough decision, because they did provide an interesting window into dysfunction.)

Anyway, it occurred to me as we were speaking that this person’s position on the case was shaped largely by their ability to imagine themselves in Mike Brown’s shoes: they had done a bit of “harmless shoplifting” as a teenager, and certainly didn’t see themselves as someone who ought to be shot, by the police or otherwise.

This person is, in many ways, mildly criminal. They get in fights, smoke pot, and probably j-walk. Their relationships start fast and end in flames. (In their defense, they’re basically a nice person who cares about others; I hope they’re having a happy life.) They aren’t someone who deserves to have their life destroyed by imprisonment, but they are a little bit criminal.

Looking at my own perspective, I’ve never shoplifted–as a kid, if a vending machine gave me too much change, I returned it to the store. I tend to be overly rule-oriented–which explains why I harp so much on society’s lies. Lying bothers me.

At any rate, this mild criminality clearly affected my acquaintance’s opinion on the proper police response to crime; had they been a person who couldn’t imagine themselves stealing cigarettes (or cigars, or whatever,) they would not have identified so strongly with the situation.

 

I feel like this post comes down a little hard on liberals; in the interest of fairness, I feel compelled to note that these are all basically biological traits that people don’t have a ton of control over, and there are plenty of people in this world who have something good to contribute even though they have the self-control of a golden retriever in a room full of squeaky toys.

Study: Sexually dimorphic facial features vary according to level of autistic-like traits …

Sexually dimorphic facial features vary according to level of autistic-like traits in the general population.
“three-dimensional (3D) facial images were collected from 208 young adult males and females recruited from the general population. Twenty-three facial distances were measured from these images and a gender classification and scoring algorithm was employed to identify a set of six facial features that most effectively distinguished male from female faces. In study 2, measurements of these six features were compared for groups of young adults selected for high (n = 46) or low (n = 66) levels of autistic-like traits.
RESULTS:
For each sex, four of the six sexually dimorphic facial distances significantly differentiated participants with high levels of autistic-like traits from those with low trait levels. All four features were less masculinised for high-trait males compared to low-trait males. Three of four features were less feminised for high-trait females compared to low-trait females. One feature was, however, not consistent with the general pattern of findings and was more feminised among females who reported more autistic-like traits. Based on the four significantly different facial distances for each sex, discriminant function analysis correctly classified 89.7% of the males and 88.9% of the females into their respective high- and low-trait groups.”

I wonder if they controlled for family’s overall androgyny level/IQ/ethnicity.

The Genghis Khans of Europe

They say that about 1 in 200 people alive today is descended from Genghis Khan (or one of his brothers, if he had any.) Obviously most of the Great Khan’s descendants are in Asia; what about the rest of the world?

from A Handful of Bronze Age Men Could have fathered two-thirds of Europeans
from A Handful of Bronze Age Men Could have fathered two-thirds of Europeans

From the article:

“Tracking [Y chromosome] mutations allows scientists to create a family tree of fathers and sons going back through time. … Two-thirds of modern European men are found on just three branches (called I1, R1a and R1b). Our results show that these branches each trace their paternal ancestry to a surprisingly recent individual (shown as red dots in Figure 1). By counting the number of mutations that have accumulated within each branch over the generations, we estimate that these three men lived at different times between 3,500 and 7,300 years ago.”

Female genetics–mitochondrial DNA–show no such feature. “… when looking at this maternal tree, there is no similar explosion. This indicates that whatever factors were responsible for this pattern were specific to men.”

This seems reasonably strong evidence that we aren’t just looking at something that could be explained away as founder/bottleneck effect, because I would expect such an effect to act equally on males and females. However, I don’t know if anyone has adequately addressed the question of patrilocality.

On a potentially related note, another study came up with this graph of Y chromosome diversity over time

From,  A recent bottleneck of Y chromosome diversity coincides with a global change in culture
From,
A recent bottleneck of Y chromosome diversity coincides with a global change in culture

 

Now if you ask me, these look like they’re describing the same phenomenon, but the dates are supposedly different.

A couple of thoughts:

1. I really really wish they’d made the Y Chromosome graph bigger and spread it out more so I can actually see what’s going on. According to the article summarizing the paper, the Siberian population did not suffer a decrease in Y chromosome diversity at this time, but I can’t tell it from looking at the graph.

2. Wow, look at the African Y chromosome diversity drop and then never fully recover. The Near East Y-diversity (the orange part) shoots up much higher than it was initially after the drop, as does the European. If the suspicion that farming was the cause of the drop is correct, then it looks like African Y chromosomes never quite recovered–consistent with the theory that African horticulture has traditionally been easy enough for women to do, leading to polygyny, leading to a few males dominating most of the women and the other males being excluded, etc. See, eg, West African Marriage and Child-Rearing Norms vs. African American Norms. (I’ve got another post on the subject, but it’s not going up for a few more weeks.)

3. What’s been happening to mtDNA diversity in the past few thousand years?

 

So was it agriculture? Or were did agriculture just make people sitting ducks for horse-born invaders? Or perhaps both?

Oops, Looks like it was People, not Pots

There’s an exciting new study on Bronze Age genetics that you’ve probably already heard about but I’m gonna post about anyway because stuff like this is kind of like our core competency around here.

Summary: Scientist people sequenced genomes (did fancy lab things with genetics) on 101 dead Europeans/Asians from a few thousand years ago, to try to figure out who they were and where they came from.

One of the big anthro/archeology debates over the past 70 years or so has been whether the different layers of cultural artifacts (eg, pots) represent things being traded while people stay put, or people invading and bringing their new stuff with them.

To put it in a modern context, if you saw a picture of people from Papua New Guinea taken in 1900, wearing traditional tribal clothes, and then saw a picture taken a few decades later of people from Papua New Guinea wearing Levi’s and T-shirts, you might wonder if the people of PNG had gotten some new clothes, or if some people wearing Levi’s had gone to PNG.

The archaeological assumption pre-1940 or so was generally that different layers of cultural artifacts represented actually different groups of people, who had probably invaded and slaughtered the previous group of people. For a variety of reasons that you can probably figure out on your own, this view fell into disrepute around the mid 1940s, and so was replaced with the peaceful assumption that new cultural artifacts probably spread primarily through trade, not warfare. This is expressed through the phrase, “Pots, not people,” meaning that the pots were moving around, not the people.

So now we can sequence ancient genomes and shit, so we can actually take a look at the people in ancient burials and try to figure out if people in Layer of Pots A are related to people in Layer of Pots B, or if they are a totally different group of people. This is like squinting at the photographs of Papua New Guineans and trying to figure out if the people wearing the clothes look like they come from the same group, but with lab tools and science.

From an archaeology/anthropology perspective, this is big stuff people have been debating about for over a century.

Conclusions: The Yamnaya are the Indo-Europeans (or proto-Indo-Europeans.) They started out around the Ukraine, then about 4,000 years ago, they spread out (cause they had horses and wagons and chariots and such with wheels,) toward the west and east. In Europe they became the Corded Ware Culture. The Corded Ware may have headed toward the Urals and became some of the ancestors of the Indo-Iranians, but that’s still fuzzy.

The Yamnaya had high (relatively) rates of lactose tolerance, so they probably helped spread that gene/the gene helped spread them. Blond hair and blue eyes are not Yamnaya traits–those came from elsewhere. They probably had pale skins, but so did most of the people already in Europe, so they didn’t change that.

I had already figured the Yamnaya were the PIEs (along with a bunch of other people paying even vague attention to the field,) but apparently my rough mental estimate of the time frame was off. 4,000 years ago is not that long–we have quite abundant records of life 2,000 years ago, so imagine what sorts of records or rumors those Greeks and Romans had about life 2,000 years before themselves.

There is much that we once naively took as fact, then skeptically decided was myth, then decided was fact again, like the existence of Troy. (Of course, there is also much that has turned out to be actually false. Like Herodotus’s dog-sized ants.) Perhaps some more of what seems mere myth in the Greek and Roman accounts will turn out to have some basis in history.

On the eastern end of the geographic range they surveyed, the steppe-folks out there were later replaced with a more Asian population that looks more closely related to the Native Americans (possibly descended from a population ancestral to both them and the Native Americans.)

I don’t know yet just how violent the invasion was–the existing European population was not wiped out, a la the Dorset. The groups mixed; modern Europeans (and many Asians) are a mixture of many population waves. But we do know now that these were people, not just their pots.

Just about the best thing I could find today (light and BMI):

“The results of this study demonstrate that the timing of even moderate intensity light exposure is independently associated with BMI. Specifically, having a majority of the average daily light exposure above 500 lux (MLiT500) earlier in the day was associated with a lower BMI. In practical terms, for every hour later of MLiT500 in the day, there was a 1.28 unit increase in BMI. The complete regression model (MLiT500, age, gender, season, activity level, sleep duration and sleep midpoint) accounted for 34.7% of the variance in BMI. Of the variables we explored, MLiT500 contributed the largest portion of the variance (20%).”

From “Timing and Intensity of Light Correlate with Body Weight in Adults” by Kathryn J. Reid, Giovanni Santostasi, Kelly G. Baron, John Wilson, Joseph Kang, and Phyllis C. Zee.

Peter Frost and Amygdalas

(I promised I’d get to this.)

Amusingly, Peter Frost, over on Evo and Proud, just recently posted, “Are liberals and conservatives differently wired?“, which describes some of the recent studies on the subject and draws conclusions broadly counter to my own. I thought you should know.

Actually, I suspect that most of the reason for or ‘disagreement’ is that we are using a different organizing schema to class people as “liberal” or “conservative.” Frost is starting with people’s self-reported affiliation, noting the differences found in the experiments, and then noting the (rather large) ethnic differences between the two groups and speculating that much of the observed difference may be primarily ethnic, rather than some grand approach to principles.

I started by first controlling for race, because otherwise (IMO) we end up smushing most of the non-whites into incorrect categories by assuming that they are voting for candidates and policies for the same reasons as whites. IE, “attitude towards blacks” and “attitude toward people who are ethnically different from yourself” might be roughly synonymous if you happen to be a white person who lives near black people, but they’re not at all synonymous if you happen to be a black person. Of course black people tend to vote for candidates who seem most likely to not be racist against black people, but that’s not the same as being liberal. (That’s just common sense.) However, since we live in a country where the majority of people are white, we tend to default toward the white POV when talking about political affiliation, and so many people who are not actually liberal at all may call themselves liberal just because they vote for the Democrats (and possibly, though I suspect less likely, vice versa.)

Any study looking for neurological differences between “liberals” and “conservatives” that just uses self-reported political orientation and doesn’t control for ethnicity seems rather dubious. If it turns out that all of my understanding of neuroprocessing is compromised, I’m going to be sad and will have to re-research everything.

Once you factor out the wonky racial dynamics, I think there is actually such thing as more or less liberal people. In the case of the British study Frost cites, I strongly suspect that the Muslims who vote Labour are actually quite conservative. Likewise, African Americans have very high rates of church attendance and strike me as fairly conservative overall, though not as conservative as most Muslims. The same is more or less also true of American Hispanics and Asians, while most white Europeans strike me as more liberal than American whites.

Studies: Disgust, Prisoner’s Dilemma

Disgust leads people to lie and cheat; cleanliness leads to ethical behavior

and

Prisoners better at Prisoner’s Dilemma than non-Prisoners

 

Quotes:
“… In one experiment, participants evaluated consumer products such as antidiarrheal medicine, diapers, feminine care pads, cat litter and adult incontinence products. In another, participants wrote essays about their most disgusting memory. In the third, participants watched a disgusting toilet scene from the movie “Trainspotting.” Once effectively disgusted, participants engaged in experiments that judged their willingness to lie and cheat for financial gain. Mittal and colleagues found that people who experienced disgust consistently engaged in self-interested behaviors at a significantly higher rate than those who did not.

“In another set of experiments, after inducing the state of disgust on participants, the researchers then had them evaluate cleansing products, such as disinfectants, household cleaners and body washes. Those who evaluated the cleansing products did not engage in deceptive behaviors any more than those in the neutral emotion condition.

“At the basic level, if you have environments that are cleaner, if you have workplaces that are cleaner, people should be less likely to feel disgusted,” Mittal said. “If there is less likelihood to feel disgusted, there will be a lower likelihood that people need to be self-focused and there will be a higher likelihood for people to cooperate with each other.” ”

SO GO WASH YOUR HANDS!

and…

“for the simultaneous game, only 37% of students cooperate. Inmates cooperated 56% of the time.

On a pair basis, only 13% of student pairs managed to get the best mutual outcome and cooperate, whereas 30% of prisoners do.

In the sequential game, far more students (63%) cooperate, so the mutual cooperation rate skyrockets to 39%. For prisoners, it remains about the same.”

A several things may be going on:
1. Defecting on your fellow prisoners may have really negative consequences that college students don’t face.
2. Prisoners may identify strongly with each other as fellow prisoners.
3. Prisoners may be united by some form of hatred for the people keeping them in prison, leading them to cooperate with each other over outsiders even when they don’t like each other.
4. Prisoners may have been through enough bad crap already in their lives that the promise of a few cigarettes seems trivial and not worth defecting over.
5. Prisoners are drawn disproportionately from a population that happens to have strong norms or instincts about not defecting.
6. College students are jerks.