Wealth, Reason Weaken Culture

What could cause rich healthy peaceful societies like ours to so consistently become “decadent”? The answer may lie in how DNA and cultural evolution differ.

Humans pioneered cultural evolution, which is what has allowed us to evolve so fast, into so many different niches. Cultural evolution, however, was layered on top of DNA evolution, which still continues. Thus our behavior often has contributions from both DNA and culture. And as DNA changes much slower than culture, DNA likely contributes more to the relatively stable context independent parts, while culture contributes more to the faster changing more context dependent parts.

We can see two key ways that this difference matters. First, sometimes unusual wealth makes cultural evolution goes bad, due to low variety, weak selection, a fast changing environment, and high rates of internal culture change. In this case, we expect cultural evolution to induce a drift from more culture to less adaptive versions. We also expect culture to come to exert a weaker pressure on behavior, relative to DNA.

Second, culturally transmitted behaviors are often justified in terms of explicit claims and arguments, claims and arguments that are often confused, weak, and incoherent. To function, culture only needs claims that can be understood in the usual contexts, and justifications that are plausible enough to be widely accepted. They don’t need to actually be coherent or true.

However, when a culture allows and even encourages an unusually large amount of abstract reasoning over an unusually long time, that reasoning is likely to undermine that culture’s key concepts, claims, and justifications. Changing them into more justifiable alternative versions, and making people less believe in them, or follow their recommendations. But as DNA based behavior is not mediated so much by explicit claims and arguments, it is less undermined by a burst of abstract reason.

Thus when cultures undergo either a burst in either wealth or abstract reason, cultural influences on behavior should get weaker, compared to DNA influences. And the longer either of these processes continue, the more of this change we should see. Different cultures should tend to converge more to a common DNA-driven human style that less reflects the details of that particular society’s history or context.

In the last few centuries humanity has seen an increase in wealth that has weakened its culture selection process, and also a big increase in abstract reasoning. The above analysis thus predicts that our behavior has drifted to become less based on culture, and more on DNA. To see what that implies more concretely, let us review which aspects of behavior are more vs less set by culture vs DNA.

First, DNA seems to set about half of basic levels of IQ, temperament, personality, mental illnesses, and sexual activity, while culture sets most of our beliefs, languages, norms, status markers, technologies, institutions, organization features, and talents acquired from practice.

Behaviors need in infants, before we’ve had a chance to acquire much culture, tend to be encoded in DNA. Also, behavioral aspects that were robust across our primate ancestors are almost surely encoded in a lot DNA. Such as thirst, hunger, sleepiness, lust, dominance, parenting habits, and reactions to physical pain and discomfort. Stuff that was pretty constant across a long period for our forager ancestors may also be encoded in DNA. Such as language, basic reason, egalitarianism, prestige, artistic appreciation, a love of travel, pair-bonding, and promiscuous tendencies.

Finally, our tendencies to do particular things in particular contexts requires a lot more context dependent detail to than does our tendencies to withhold effort, and not do stuff. Thus our laziness, selfishness, and myopia are more likely encoded in DNA, while the particular things that we might do if we overcame such inertia are more likely encoded in culture.

The prediction, then, is that as we’ve gotten rich and more into abstract reasoning over the last few centuries, our behavior has become less set by culture, and more by our basic animal and forager natures. We focus on hunger, sleep, lust, dominance, comfort, while preferring language, prestige, egalitarianism, and promiscuity. And we are more lazy, selfish, and myopic, and so just do less when we can get away with that. “Decadence” doesn’t seem like such a bad world for such a state.

Many societies in history have gotten rich for a while, and for that while plausibly suffered a weaker cultural evolution process, which plausibly contributed to their subsequent decline. It is less clear which ones allowed for a burst of abstract reasoning, though the ancient Greeks seem a strong candidate. The above analysis suggests that we are now more similar to the people of these peak rich reasoning periods, than to the people of most other historical periods.