One of the first lessons that must be learned from this important book is that the WEIRD mind is real; all future investigation of “human nature” must be complicated by casting a wider net for subjects, and we must stop assuming that our ways are “universal.” Offhand, I cannot think of many researchers who haven’t tacitly adopted some dubious universalist assumptions. I certainly have. We will all have to change our perspective.
Many of the WEIRD ways of thinking, Henrich shows, are the result of cultural differences, not genetic differences. And that is another lesson that the book drives home: Biology is not just genes. Language, for instance, was not invented; it evolved. So did religion, music, art, ways of hunting and farming, norms of behavior and attitudes about kinship that leave measurable differences on our psychology and even on our brains.
To point to just one striking example: Normal, meaning non-WEIRD, people use left and right hemispheres of their brains about equally for facial recognition, but we WEIRD people have co-opted left-hemisphere regions for language tasks, and are significantly worse at recognizing faces than the normal population. Until recently few researchers imagined that growing up in a particular culture could have such an effect on functional neuroanatomy.
The centerpiece of Henrich’s theory is the role played by what he calls the Roman Catholic Church’s Marriage and Family Program, featuring prohibitions of polygamy, divorce, marriage to first cousins, and even to such distant blood relatives as sixth cousins, while discouraging adoption and arranged marriages and the strict norms of inheritance that prevailed in extended families, clans and tribes. “The accidental genius of Western Christianity was in ‘figuring out’ how to dismantle kin-based institutions while at the same time catalyzing its own spread.”
The genius was accidental, according to Henrich, because the church authorities who laid down the laws had little or no insight into what they were setting in motion, aside from noticing that by weakening the traditional bonds of kinship, the church got rich fast. One of Henrich’s goals is to devalue the residual traces of “Great Man” history, so he would be reluctant to rely on any ancient documents that came to light recounting the “real” reasons for the church’s embattled stand on these issues. As a good evolutionist, he can say, “The church was just the ‘lucky one’ that bumbled across an effective recombination of supernatural beliefs and practices.” But as for why the church fathers enforced these prohibitions so tenaciously against resistance over the centuries, this is still a bit of a mystery.
Around the world today there is still huge variation in the societies where cousin marriages are permitted and even encouraged, and societies in which it is close to forbidden. There are good reasons for supposing that our early hominin ancestors were organized for tens of thousands of years by tight kinship relations, which still flourish today in most societies. So what happened in Europe starting in the middle of the first millennium was a major development, largely restricted to or at least concentrated in certain cultures where positive feedback turned small tendencies into large differences that then turned further differences into the birth of WEIRD culture and WEIRD minds.
This is an extraordinarily ambitious book, along the lines of Jared Diamond’s “Guns, Germs and Steel,” which gets a brief and respectful mention, but going much farther, and bolstering the argument at every point with evidence gathered by Henrich’s “lab,” with dozens of collaborators, and wielding data points from world history, anthropology, economics, game theory, psychology and biology, all knit together with “statistical razzle-dazzle” when everyday statistics is unable to distinguish signal from noise. The endnotes and bibliography take up over 150 pages and include a fascinating range of discussions.