The Science of How We Become Human

Reviewing the book “Becoming Human: A Theory of Ontogeny” By Michael Tomasello

This book is about ontogeny, meaning the development of an organism. From the very beginning of life as a fertilized egg to an adult organism. Here the term is applied to human ontogeny, from a cognitive perspective. Children obviously don’t come into the world thinking like adults, and there isn’t a quick transition period from child to adult. Rather, there is a countless gradual changes over many years. It is largely inspired by the work of the Soviet psychologist Vygotsky on children’s development (he coined the zone of proximal development if you ever took a psychology 101 class). But it adds the latest research on developmental psychology to Vygotsky’s model.

He often focuses on comparing children with great apes since that’s a clear line where the human cognitive system has developed. If they are already present in apes, they are not human by definition, although sometimes this gets blurry when the processes aren’t black and white. Something that I took from the book is really how more cognitively developed children are compared to great apes. I had the impression that until a certain age, they were roughly at the same level, and they are in general behaviour and intelligence. However, when tested with key human cognitive features, especially social and moral ones, really young children outperform great apes by a large margin.

For example, apes have abstract cognitive representations, but early humans easily understand perspectival representations. Meaning that I can see a situation not only from my perspective but from yours as well. We sort of take this for granted, but it is a quite developed cognitive skill. In addition, modern humans have not only a perspective representation but also an objective one. We understand that in addition to both our perspectives, there is an “objective” perspective that corresponds to the real world, and it is independent of us.

But where humans really shine is social interactions. We are defined by culture, and thus biology has evolved to serve us. We have such a long period of immaturity, which is counter-productive and dangerous, to allow such a complex adaptation to the specific culture an individual is born in. The brains of young chimpanzees are about half of their adult size; they reach 90 per cent of their adult size by two years of age. But the brains of humans are only 20 per cent of their adult size at birth and do not reach 90 per cent of their adult size until eight years of age.

Another important takeaway I got from the book and which I was unaware of is that young children interact mostly with adults first. It would be reasonable to assume it was mostly with peers, but it is not. That only comes later. All the meaningful interactions are with adults, and it is with them that they learn joint attention, cooperative communication, and social imitation. And this interaction is not only pragmatic in terms of life skills (such as breaking a coconut). If an action has no clear outcome, apes do not imitate it. But human children do because they assume it is some kind of culturally significant behaviour (like a ritual). Joint attention, one of the skills mentioned, is particularly important, and it is covered extensively in the book. The foundation of human beings is cooperation, but that requires us to “sync” our cognition into a shared goal, which is difficult and apes do not do reliably, their cooperation is always instrumental. Yet this emerges as early as the first year of life in humans, and by the second, they are vastly better than any other ape.

This ontogenetic development is both genetically primed and socially constructed. Children are wired to learn from adults and develop the skills required to integrate successfully into our hyper-cooperative society. But such skills are basic and have variation from culture to culture, which the children learn as they grow.

While I did like the book, it honestly felt overkill. I ended it having the impression that I just had an entire college module on developmental psychology. It was incredibly detailed, going into each experiment as he was building his case. Of course, this makes it very well-grounded, but it does negatively affect the reading experience. I think a lot of things could have been spared and still deliver the point well but a lot more succinctly. I am honestly baffled at how well-rated the book is, given the level of detail. Maybe they are all developmental psychologists or somehow managed to enjoy the little details a lot more than I did.

The book does what it promises: a very comprehensive theory of human ontogeny. But it almost does it too well and is quite academic. If you want to dive very deeply into the topic, this book would be excellent. On the other hand, if you just want a brief overview of human development, I would look into other sources.

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Tiago V.F.