In-marriage Out-marriage oscillation

Previously (Group Selection of Humans) I convinced myself that humanity finds a balance between in-breeding and out-breeding. I now think that the balance is more like an oscillation, as balances often are. Here’s the story:

There was a discussion about ISIS that seemed to assume that male talk was the full story (https://plus.google.com/u/0/117663015413546257905/posts/5DfjTXF5agm). I tried to suggest more real-world reasons for the vigorous opposition to Western values:

An interesting aspect of the IS area is that a lot of marriages are to cousins, preserving family power and status. The great threat to family status is female education and power from merit. I suspect that it would be useful to understand female opinion in the area as well as listening to the cacophony of males talking about arcane knowledge.

Which everyone ignored, except for David Friedman who responded:

"An interesting aspect of the IS area is that a lot of marriages are to cousins"

Any more than elsewhere in the Islamic world?  I've seen figures for Iran, where that is also true, and it's clear in Islamic literature that cousin marriages are favored. Consider, for instance, the farmer who understands the speech of animals in an early story in the 1001 nights, where the fact that his wife is his cousin is clearly seen as a plus.

I thanked him for this:

Thanks, that perhaps explains why pushback against modernity is common in the Moslem world. It is an interesting contrast to Christianity where rules against incest were expanded to cousins for a time (unless you paid the Pope). …

Whether it had much to do with indulgences, there is no doubt that Europe freed itself from the inbreeding which, I’ve argued, was crucial in the development and maintenance of human social behaviour. But human behaviour had recently (on an evolutionary timescale) changed to feature larger culture-based groups (see What is Culture for). At times the inbred extended family groups continued within the larger groups, as we see in the Middle East now. In Europe now we see the opposite, with random marriages meaning there is no genetically coherent groups within the culture based groups. This has immediate advantages in strengthening the culture-based group, as we see in the very coherent European nation states that conquered much of the world in the 19th Century, but there are long term costs.

It changes the evolutionary incentives. Opposition to non-cooperating individuals has a cost. And now there is no direct advantage to an individual’s genes to take those actions. With that opposition weakened, the proportion of people not cooperating will rise. Indeed it will continue to rise until that culture-based group starts to malfunction. It might get to the point of losing in struggles with groups which include those extended family subgroups. But perhaps it doesn’t get that far. Perhaps as society gets dysfunctional, with lots of bad guys causing trouble, then there is incentive for families to try to hang together via cousin marriages.

So we might reasonably expect an oscillation between inbreeding with extended family groups, and outbreeding with individual loyalty going directly to the culture-based group.

I believe that cousin marriages and extended families creates a very conservative environment. In particular they have to suppress individual freedom to prevent random marriages. Freedom and individual initiative has been the most powerful advantage of the West in recent times, and very likely for other successful culture-based groups in the past. But the disadvantage will eventually catch up with us, if we let it.

What is Culture For?

[I've said this stuff a number of times, but there is no obvious URL to point to, so here's a summary]

Seventy thousand years ago humans were very different. Superficially it wasn't that different from more modern hunter gatherers. People lived in groups (quite in-bred promoting cooperation). They made tools. They talked about the weather and the food options and who was doing what with whom. But look closer and there is little to call art or music, and nothing changes over thousands of years.

Then culture started and around 30,000 years ago it swept the world. Most obviously there is art, and there is invention and change in tools and clothing and housing. What I mean by "culture" is things that groups adopt to distinguish themselves from other groups. Groups love to distinguish themselves:

• "We are the group that dresses like this"
• "We are the group that speaks and understands this language and these idioms"
• "We are the group that makes this sort of pottery"
• "We are the group that plays and enjoys this sort of music"

And these things require skills that take years. Foreigners can't just walk in and blend in.

Culture takes up a lot of brain power and a lot of time and effort. Why was it so successful in displacing the simple lifestyles that preceded it?

Intergroup conflict is a characteristic of our species, and indeed of related species such as chimpanzees. For a graphic discussion of this, see Jared Diamond's book The World Until Yesterday. Before Culture, groups were limited to ones where everyone knew everyone else. Culture allowed us to create groups that were defined by common culture. These could be much larger.

So that's it. Culture allowed us to create big groups that beat up the small groups of pre-cultural humans. At first the pre-cultural females would be absorbed by the victors, diluting the culture genes and slowing things down. But by 30000 years ago the dilution process became insignificant and the takeover of cultural genes went very rapidly to completion.

We love cultures generally and our own particularly. So this is not quite the story we would want to hear. But we need to understand how we got here if we are going to make good decisions about where to go.

My mum versus the experts

All 5 of my parents' granddaughters are now married (and what an inspiring quintet (quintuple?) of young women they are). Thinking about my mother I thought I'd mention some of her battles with the (self-appointed, pseudo-) experts.

1. My mum insisted that butter was healthier than margarine, against the "experts" put up by the processed food industry. This has recently been proved right. She was also strong on the importance of other particular foods: brains (from sheep) and liver. Her ideas on these things come down from her ancestors. It is shocking how easily we abandon traditional knowledge these days. Expertise used against traditional knowledge needs a high standard of proof.

2. My mum was a great believer in the health benefits of sunshine. This has been proved right, though the anti-sun propaganda continues to push the damaging zero-sun policy. I should say that my reading leads me to believe that this is not just about vitamin D. The body uses UV to break down toxic organic molecules in the blood. This is extra important for people (like me) whose liver is not working 100%. An example of this, that is not in dispute, is bilirubin that causes jaundiced babies.

3. My mum was a strong believer in fresh air in houses. We are faced with a strong push from the Green movement for housing to be built tight as a drum and heated and cooled with heat pumps. I think my mum will be proved right again. Even if you are not in a Radon area (are you sure?), sealed houses get various sorts of toxic build up. All my life I worked in air-conditioned offices and I'm very pleased to have escaped that.

[update: The point I forgot to make is this: The expert brand is badly tarnished. This needs to be addressed by creating an environment where: (a) There is an open vigorous investigation of facts that are relevant to public policy and people's lives; (b) This needs to include nailing not only false claims, but also identifying those who are trying to deliberately mislead (this has to be seen to be impartial); (c) Identifying the real experts who know the facts and the relevant mathematics.]