Joseph Henrich is an anthropologist with a rather atypical background since he started in aerospace engineering before switching to anthropology. I came across him because his latest book The WEIRDest People in the World is widely shared on X. Maybe when I have the courage to finish it I’ll talk about it too.

The Fundamental Question

This book tries to answer a question I’ve often asked myself: fundamentally, what’s the difference between humans and animals? A question that may seem a bit naive, but which requires profound erudition to answer.

Intelligence: Is That Really What Distinguishes Us?

In an obvious way, you’d simply say intelligence. Indeed, when you look at human productions compared to the rest of the animal world, there’s clearly a difference. Scientists, taking nothing for granted, conducted a curious experiment (plenty of experiments like this are described throughout the book).

Babies vs Apes: A Surprising Experiment

They compared the cognitive performances of babies with apes. All other exercises that require logic, raw computing power, in short everything we more readily attribute to intelligence, are dominated by apes. We discover that apes are slightly better in most exercises except one: imitation. Babies and more generally humans are imitation machines.

IQ Isn’t Enough

You surely know the famous IQ map that circulates all over the web, we see a clear hierarchy: Asia > Europe > Africa to schematize a bit. Now what happens if we take the best Europeans and plunge them into the Arctic or the Australian desert, how long do these high IQs survive? What I just related are not experiments but real situations that occurred and resulted in the death of the explorers concerned, even though the “low IQs” have been living in these areas for millennia.

Two Essential Conclusions

Two conclusions then emerge from these experiences: what we commonly call intelligence is the result of a slow process of trial-and-error and communication of human beings across eras; a large part of this intelligence is unconscious and expresses itself without our knowledge.

For example, there’s a chapter dedicated to prestige. Some people, myself included I admit, have a tendency not to give too much importance to prestige, reputation, gossip. I tend to take these as futile and very superficial things. Nothing could be further from the truth. Every sufficiently large group needs to establish rules to survive, if a group member violates certain rules they endanger the group’s life, gossip and the resulting bad reputation allow excluding an individual who would be harmful to the group. For prestige it’s the opposite: a hunter with a good reputation will naturally attract all the apprentice hunters and from generation to generation the techniques will improve and the community will become more prosperous, prestige is literally a signal that the community auto-generates and which basically says “do like him”. Here’s an example of a form of intelligence that expresses itself without the main actors’ knowledge without them realizing it. In the end, the groups that survive and dominate others have more effective mechanisms of this kind than others. These organizations depend of course on the individuals who make up the groups but also and especially on the environment. Thus the author will at some point relate how blue eyes appeared or why populations in tropical countries eat chili peppers. I’ll detail this last one a bit.

The Fascinating Example of Chili Peppers

We just saw that prestige was a signal. Elderly people are prestigious by default because they survived and passed the test of time. Chili peppers apparently give a slight advantage in terms of life expectancy to those who consume them daily, it notably helps reduce parasites in meat. The only problem is that it’s extremely unpleasant, moreover the only mammal that consumes chili peppers is humans. How could this practice become widespread? And precisely where it was most needed, that is to say tropical countries. Chili pepper consumption gave an advantage, even though those who consume it ignore all these advantages.

Those who consume chili peppers live slightly longer, so among the elderly there will be an overrepresentation of chili pepper eaters and since young people tend to imitate the old (Before the 21st century when the world was stable from one generation to another this was the case, today it has changed a bit), here’s how over generations everyone starts eating chili peppers without knowing why. Young people force themselves to eat it and reprogram their brain to transform pain into pleasure. I find this incredible! If I had known we were going to talk about chili peppers when I opened this book.

Cultural Knowledge: Beyond Individual Intelligence

This is why scientists even with their high IQ cannot survive in hostile territory, the essential knowledge for survival cannot be deduced but is the fruit of a very slow cultural evolution over generations. Hunting techniques, how to build an igloo, how to track prey, almost all human knowledge proceeds this way. Individuals make optimal choices without knowing why, and no one alone could reproduce all these techniques and knowledge. Communication and exchanges between individuals are essential.

Gene-Culture Coevolution

What’s interesting is that cultural knowledge influences our ways of life and our customs but also influences our biology, the best example that comes to mind is cooking food. Indeed, the latter has profoundly modified our anatomy, reduced intestinal transit because cooking is in fact a pre-digestion, foods are also softer so facial muscles have become finer and less coarse, which left room for the brain to gain space and grow. Fire literally made us more intelligent.

Conclusion

Many other aspects are addressed in the book: why faith (obeying without understanding) appeared, female polygamy (yes, yes, it existed, you’ll quickly understand why it didn’t spread unlike that of men), the book is really worth reading even if it’s quite hefty and a bit tedious. It hammers “cumulative culture” I don’t know how many times in this work.

This book makes you more humble because finally you realize that old customs are not always the haphazard fruit of arbitrariness and that if we’re here today it’s because our ancestors weren’t totally stupid. I know it’s a bit counter to the dominant ideas that want to make a kind of blank slate of the past. I also find that conversely the book allows you to better get rid of the weight of traditions, as you learn why they appeared you’ll have less tendency to cling to them especially if you see that the world has changed too much and that the custom, habit has become totally obsolete compared to the current world. In short, we understand ourselves better and we understand the world better.