Joseph Henrich - The Secret Of Our Success (Princeton University Press, 2016) *****

I was more than impressed by Henrich's other, more recent work - The Weirdest People In The World - that I went back to his successful earlier book "The Secret Of Our Success". Henrich is an anthropologist and professor of human evolutionary biology at Harvard University. 

In this book, Henrich explains how nature and nurture are in fact meaningless concepts, since humans have evolved, also genetically as the result of cultural evolution, and we have changed nature around us as well. We depend on our cumulative culture for survival, we need to live in cooperative groups, using allo-parenting, the division of labour and information, and on our communicative abilities to be what we are today: a biological anomaly, a new kind of animal. The chronological concept that we are developed in nature, and then later developed our culture is an erroneous one: our culture affects our genes and our genes affect our culture: both co-evolve, and are still co-evolving. Henrich provides numerous examples from biology, cognitive sciences, linguistics, economics, history and anthropology to build his convincing case. 

We are a cultural species, whether we want to or not, and understanding this, will help us understand the perspectives of others even better. We are not determined once and for all. Henrich ends his book with eight insights that will help this understanding and paving the way for future research and human progress.  Especially his examples related to language, communication, cooperation and collective brains show how collaborative and communal efforts have led to benefits for us all. Henrich gives examples of how highly intelligent and resourceful explorers did not manage to survive in difficult situations (from the arctic to the Australian desert), despite their brains and technology, while local indigenous people did. They lacked the collective intelligence of the local tribes. 

Henrich's sweeping picture of humanity is well-substantiated and easy to read. For instance, his example that humans can outrun quadrupeds in terms of endurance, and have done so daily as hunters, for the simple reason of using gourds of water they took with them to compensate for sweating and dehydration. The cultural invention compensates for the natural deficit, turning it into an advantage, and thus better chance of survival. 

It's a humbling and insightful book, well-written and compelling. Henrich concludes:

‘To move forward in our quest to better understand human life, we need to embrace a new kind of evolutionary science, one that focuses on the rich interaction and co-evolution of psychology, culture, biology, history, and genes. The scientific road is largely untravelled, and no doubt many obstacles and pitfalls lie ahead, but it promises an exciting journey into unexplored intellectual territories, as we seek to understand a new kind of animal.’

David Reich - Who We Are and How We Got Here (Oxford University Press, 2018) ****½

Up until a few decades ago, knowledge of pre-historic humanity could only be collected from archeologic finds. Bones and artifacts only partly revealed their mysteries, but now genetics becomes a new method to allow us to get a better understanding.

David Reich and his teams specialise in paleogenetics, the science of genetics in ancient humans, which created a true revolution in our understanding of our past, overturning many standard theories about migrations and mixing of peoples around the globe.

Some of these findings include: the fact that most Europeans and Asians have a few percent of Neanderthal genes in their genome, demonstrating that interspecies sex occurred some 50,000 years ago or earlier. He also demonstrates how the early humans migrated out of Africa in different waves, with different outcomes in Asia and Europe, or how native Americans moved into the continent in three waves, some of which can be timed, others not. The insight generated by human population genetics also sheds some light on the interaction between peoples within the same continent. In Europe, it is clear that some peoples completely disappeared as the result of viral contamination by tribes that migrated into their geographic area (as in current Germany), or were exterminated, rather than the merging of cultures which was always assumed. In Iberia, for instance, it is clear that in some incumbent human tribes all men were killed, because the existing genetic traits could only be traced back through mitochondrial DNA - through the feminine lineage - meaning that women were kept alive. It also shows the importance of dominant men in history, including Genghis Kan, who through and power and wealth managed to have a substantially more than average offspring.

Reich's discoveries also led to quite some reaction from anthropology and archeology academia, which is not surprising considering the fact that many acquired ideas were undermined, but questions were also raised about the ethical aspect of conducting genetic research on ancient burial sites, with or without the consent of the tribes still living there. The issue became especially sensitive in the context of Native American tribes: genetic insights could confirm or disprove a genetic lineage between current tribes and the bones found in burial grounds.

The genetic findings also allow to measure the effect of the caste system in India, demonstrating that despite the thousands of years of cohabitation, genetic distinctiveness of brahmins and untouchables has remained.

On the positive side, this new technology allows for a much more precise understanding of how we as humans are all the same species, with lots of common ancestors, who often intermingled and migrated in ways that were never even considered a decade ago.

It is fascinating, illuminating and highly promising for even more research findings in the coming decades.