Cultural Brain Hypothesis

Michael Muthukrishna wrote,

One key insight from cultural evolution is that our behaviour is rarely a function of causal understanding. Cultural evolution explains how our species creates and thrives in a world too complicated for any of us to understand. For at least the last 50,000 years and probably longer, we have lived in a world of accumulated technology, know-how, and ways of thinking that surpass the abilities of even the smartest among us—cumulative culture. Our lack of causal understanding is masked by an illusion of explanatory depth; we assume we understand and have reasonable causal models for our beliefs, behaviours, and technology. That illusion is shattered only when we’re asked to explain specifics. For example, you may have some sense that you understand: (a) how a flushing toilet works, until you’re asked how the water flushes everything away and returns to the same level. . .All of this is to quickly illustrate that the world is not only complicated, but even more complicated than our psychology allows us to believe. Instead, our beliefs and behaviours are shaped by our incentives and by those around us. We prefer to believe things that align with our self-interest and we internalise the beliefs and copy the behaviours of those who are successful or those who others copy. As this process filters beliefs and behaviours over generations, most people acquire the accumulated package of past successes, and so conforming to the majority also becomes a successful strategy. [links omitted]

. . .In the cacophony of opinions on the COVID-19 crisis, how do people deploy their many social learning strategies to decide whom to listen to? How do we identify who has relevant expertise if we’re listening to experts at all? Are the learning strategies themselves learned? What is the role of trust, costly and sincerity displays? And how does a psychology evolved for vicarious information acquisition with little direct access to the truth, nor sufficient causal models, interact with a world in which evidence is easily manufactured and electronically disseminated? How do we decide which fact checkers to trust and how do we know what is and isn’t so?[again, links omitted]

I put it this way: We engage in behaviors and hold beliefs without understanding why we behave the way we behave or why we believe what we believe. This is not a failure of rationality. It is the human condition.

Cultures are preserved because humans are copiers. Cultures differ because we do not all copy the same people. Cultures evolve because copying is imperfect, people innovate, and changes in the competitive environment cause some cultural practices to become extinct and others to survive.

I recommend gorging yourself on Muthukrishna. My first taste was on The Podcast Browser, who also recommends Muthukrishna talking with The Dissenter.

Of the many links in the essay above, I followed one on the topic of innovation, by Muthukrishna and Joseph Henrich.

Our societies and social networks act as collective brains. Individuals connected in collective brains, selectively transmitting and learning information, often well outside their conscious awareness, can produce complex designs without the need for a designer—just as natural selection does in genetic evolution. The processes of cumulative cultural evolution result in technologies and techniques that no single individual could recreate in their lifetime, and do not require its beneficiaries to understand how and why they work ([12]; electronic supplementary material, for further discussion). Such cultural adaptations appear functionally well designed to meet local problems, yet they lack a designer.

. . .By our account, IQ is a measure of access to a population’s stock of know-how, techniques, tools, tricks and so on, that improve abilities, skills and ways of thinking important to success in a WEIRD world. IQ tests are useful as a measure of cultural competence, which may require cultural learning (and there may be differences in this), but not as a universal test of ‘intelligence’ as a generalized abstract problem-solving ability. The Flynn effect (for recent meta-analyses, see [141,142]) describes the steady increase in mean IQ since IQ tests were developed, approximately three points per decade. If taken at face value, then the Flynn effect renders large proportions of previous generations barely functional, but by this account, the Flynn effect becomes a measure of increased mean cultural complexity.

It’s a difficult paper to excerpt. Read the whole thing.