As I touched on earlier, there is probably something genetic underlying people’s attitudes toward altruism, or at least a genetics-environment interaction.
To be clear, we are looking at the pattern of “conservatives have a small network of people whom they would sacrifice a great deal for, and a large # of people whom they don’t really care about, with a fairly sharp distinction between them” vs. “liberals have a large number of people about whom they care a moderate amount, with no sharp distinction between levels of caring,” aka “high tribalness” vs. “low tribalness”.
Lots of other people who are not me have done a TON of work on this subject, so I am not even going to attempt to summarize all they have said and done. For now, I’m just going to try to keep this short, and limit it to my own best suspicions:
Conservatives probably are, or were socialized by, people who are genetically more closely to their communities (or ancestral communities) than liberals.
In technical terms, we are talking about levels of consanguinity. In slightly more popular terms, we’d call it levels of in- or out-breeding. Unfortunately, the term “inbred” is an insult in American (western) society, because we have strong cultural norms (memes) on the subject (memes not shared with many other parts of the world, which have very different opinions on the subject of optimal marriage partners.)
To be clear: I am NOT saying, “Hur hur hur, conservatives is dums becuz they marry their cuzins.” This is a discussion of *comparative* levels of consanguinity in one’s ancestors and in one’s community, not whether or not one married one’s cousin or raped one’s sibling.
Now, a bit of necessary background: Different people (and regions of people) have different levels of consanguinity. For example, the descendants of a group of one hundred people who got stranded on a tiny island in the Pacific with no outside contact with the outside world for a thousand years, even if they have scrupulously followed the no-cousin-marriage rule, will obviously all be very closely related to each other, and genetically distinct from outsiders. Two individuals chosen at random from this island will be very genetically similar, sharing many (if not most) traits, and sharply different from outsiders.
By contrast, take a city founded at the confluence of several major trade routes, in the midst of relatively hospitable territory. People from different ethnic groups come and go in the city, marrying and leaving descendants. Any two randomly chosen citizens could easily be more closely related to and share more genetic traits with people from hundreds or thousands of miles away than with each other. So long as no one imposes segregation, a few thousand years of mixing (or a couple of generations, take your pick,) will produce a community of descendants who are distantly related to lots and lots of people, but less closely related than the islanders to their own immediate families. Where the islanders are sharply distinct from the rest of the world, the citizens blend gradually into the world.
This implies that islanders actually share more genes with their children than the citizens. Island-altruism toward one’s family or virtually anyone on the island will therefore propagate the individual’s genes. The citizens, who share fewer genes with their own children and immediate family and only a few with their neighbors, do not benefit as much genetically from altruism. The citizen who dies for their fellow citizen is closer to an evolutionary dead end, eliminating most of their altruism from the gene pool, while an islander who dies for their fellow islander has saved a much larger proportion of their genes. However, it is not in the citizen’s interest to do nothing for their fellows. After all, those guys do share some of their genes. The citizen, then, will display low-levels of altruism toward lots of people, without much ability to distinguish “us” from “them” (because there is no sharp “us” or “them”), but not massive sacrifices beyond the small level of genetic sharing. The islander will sacrifice readily for their fellows, but has no reason to sacrifice for outsiders.
Now, truely isolated islanders are a rare exception, as they are unlikely to have much of an adaptation for dealing with outsiders due to it never coming up. With no notion of “outsiders”, such communities can be quite nice–socialistic to the point of being indistinguishable from liberal communities, even. Japan comes immediately to mind. Yes, the Japanese have had a bad history of trying to conquer the outside world and I would characterize the people as generally conservative, but Japan itself is a socialisty state with far more equality and social cooperation than the US.
American conservatives, by contrast, interact with and are affected by the outside world far more. They consequently have a much more active hostility toward outsiders.
Implication: the idea that conservatives don’t support socialism is simply a side effect of living in a multi-ethnic society. Conservatives support socialism for themselves, but not for people whom they see as outsiders. (Which is, of course, genetically sensible.) Liberals support socialism for a much broader group of people, which is sensible for their genetics. The difference between these two groups in this discussion lies not so much in their treatment of their own, but in the nature of the distinction between “their own” and “not their own”, and their willingness to extend altruism beyond their own.
Disclaimer: I have followed a genetic train of reasoning here. As I noted, memes and genes go together; it’s entirely possible that we could get identical results just by raising people in tightly-knit culturally united communities or loosely-knit culturally diverse communities, with the results being entirely environmental. In reality, I suspect there exists a semi-complicated interaction between peoples’ natural inclinations and the environment they’re raised in and/or live in, where some people are well-adapted to certain environments and will thrive in them, and others are mal-adapted to those environments and become stressed out (perhaps pathologically so,) and would probably be better off elsewhere.