The first book you’ve chosen is Ape, Primitive Man and Child, which was first published in Russia in 1930 by the famous Soviet psychologists Alexander Romanovich Luria and Lev Semyonovich Vygotsky, a book that was later suppressed by Stalin.

In Ape, Primitive Man and Child, Luria and Vygotsky put forward a theoretical framework for explaining what makes us human. They argue that there are three principal lines in the development of the creation of our uniquely human abilities: the evolutionary line, the historical line and the ontogenetic line. In order to understand who we are as human beings, we need to understand that we’re the product of all three of these lines of development. If it wasn’t for the evolution of our human genetic make-up, the human genome, then we wouldn’t be human. But, as Luria and Vygotsky stress, the evolution of our human make-up is merely the precondition for our humanity. Our genome is very similar to when homo sapiens was first around 100,000 years ago, but in terms of how we live our lives, we are incomparable to our ancestors. So, in order to fully understand who we are, we need to go beyond just the evolutionary line and we need to look at the historical line of development, and also, finally, to understand individuals you have to look at their unique social relationships, their own life history. Each human being that has ever existed on planet earth is unique, and that’s the result of the historical and ontogenetic line of development. 

Ontogenetic? 

It means individual lifespan. It’s the life history of an individual – the area really that developmental psychology studies. 

And even though it’s an old book, it’s still useful today? It hasn’t been overtaken by new findings?

I don’t think so. I think as a theoretical framework it still holds. All of the books I look at, although they don’t always reference Vygotsky and his work, you get a sense that they have been influenced by his thinking and the real breakthroughs that he made, despite only living to age 37.

Why was the book suppressed by Stalin?

Stalin tended to suppress anything that did not conform to the party doctine. Vygotsky's ideas would have been threatening because they were revolutionary – Marxist – in the true sense. He adopted the dialectical method for understanding the mind. But also he engaged with the ideas of great thinkers outside of Russia, such as Freud and Piaget, and was therefore dismissed by Stalin as a ‘bourgeois idealist’. 

Let’s go on to your next books, The Prehistory of the Mind by Steven Mithen and The Cultural Origins of Human Cognition by Michael Tomasello, which offer different theories about our evolutionary development. 

Yes, these two books really go quite far in trying to understand the emergence of our unique human abilities through evolution. Steven Mithen starts off by saying, ‘We’ve got a real conundrum here.’ Around 100,000 years ago there is some evidence among homo sapiens of novel tool-making, such as bone artefacts. But he points out that the tools that were used and made then were not that much more sophisticated than our ape ancestors. The major turning point only occurred once homo sapiens had been around for tens of thousands of years. This is what is referred to as the Paleolithic revolution, where we suddenly see far more sophisticated tools, far more sophisticated and developed hunting techniques. You have oceanic travel, cave drawings, ceremonial burials. So moving from very simple tools to a far more sophisticated ways of organising ourselves in groups and even being able to travel over oceans. Mithen says the key challenge is really to try to understand this explosion in creativity around 60,000 years ago, which doesn’t correspond with an increase in brain size – because that was a lot earlier. Brain capacity alone can’t explain this sudden leap forward. 

Wow, that’s exciting. How does he explain it?

His theory is that this explosion is as a result of changes in the nature of language. And, following on from that, he says you then see changes in consciousness within the mind. He argues that the language of early humans, pre-homo sapiens, was exclusively a social language. They used language to send and receive social information, to establish pecking orders and loyalties, etc, rather than using language for subjects such as tool-use or hunting. With larger group sizes language was an effective means of building social ties; much more effective than grooming, which is the staple form of sociability for apes, that’s the way they maintain some kind of group cohesion. Mithen argues very persuasively that this social language, at some point, gets transformed into a general purpose language. And it’s only when language starts acting as a way of delivering information about the world other than the social world, that we’re able to really start thinking about our own thought processes. He says that, as a result of that, the whole of human behaviour became pervaded with the flexibility and the creativity that characterises modern humans. 

Because the real difficulty, if you understand evolution, is that things change very slowly. But here you have this explosion. There must have been a small change in our evolutionary past that allowed language – a social language – to suddenly become a general purpose language, Mithen argues. 

Evolution alone isn’t enough to explain language?

Some argue that language could be selected for through evolution. But if you look at something as complex as having grammar, and all the aspects of a language, and you look at the evidence of how long language has been around, it hasn’t actually been around for a long time. So if apes didn’t have language, and homo erectus and homo habilis didn’t have language, how could, over the course of several 100,000 years, something as complex as language be a result of a chance mutation?

What made the change possible?

I suppose his argument is that there was this social language. Once you have language, then you can start using that language to drive your own thought process and actually think about what you’re doing – rather than just banging away at something. When you get a tool that is helpful, you’re actually looking at it and thinking, ‘Well, this isn’t good enough, I want to use it for this, maybe it would be better if it was sharper this end, and blunter at that end…’, etc. I read Mithen’s book before I read Tomasello’s and I thought, it’s really persuasive. It’s very convincing. He has a detailed knowledge of everything that we know about early man and what tools existed and suchlike.

Yes what about the Tomasello book, The Cultural Origins of Human Cognition?

This book I am equally or even more persuaded by. Tomasello argues that evolution must have endowed us with something uniquely powerful. He says the only possible solution to the puzzle of this explosion in creativity, the only biological mechanism that could have brought about these changes in such a short period of time, is a new capacity for social and cultural transmission. In other words, what he’s saying is that there is a new, uniquely powerful way of social learning. He says you can see how evolution has endowed animals with a more simple form of social learning: for instance, rat pups only eat food that their mother eats, they learn from what their mothers eat. Young birds learn their species’ typical songs by mimicking their parents. His argument is that this simple ability to learn from our fellows, not in a conscious way – animals don’t do it in a conscious way, is something evolution has endowed them with – stopped at some stage in our evolutionary past and became transformed into something a lot more powerful. What is unique about our form of social learning is that we are able to imitate and that we are able to learn things co-operatively – whilst animals are not able to think about what their fellows are doing or what they themselves are doing. We can look at what somebody else is doing and we can make inferences about their goals and intentions. What they are trying to do here? What is the intended outcome of what they’re doing? And we can look at how they actually do it, the various steps towards achieving the end product and we can look at the end product. While all the experimental studies point very persuasively to the idea that apes are only able to look at the outcome. For a while people thought apes could ape. 

They can’t?

No, they can’t. Not in the human way. They can look at the outcome of what somebody has done, and then they have to invent a way of achieving that through trial and error. So in an experiment they might see a human being using a rake to pull something towards them. Then they might realise, ‘Oh, a rake can be used as a tool.’ But they don’t understand the how. Through trial and error they might achieve the same result, or get the same result in a different way. Which is why, I would argue, in the right conditions, a clever ape could invent all the ape behaviour that we see today. An ape that is clever enough could invent all of the different ways that apes use tools, while it’s absolutely not the case that ANY human being, however clever they are, could invent from scratch X-rays, combustion engines, the harnessing of electricity – everything that humans have achieved. 

But both Tomasello and Mithen are trying to explain that same mystery, what happened 60,000 years ago?

Yes, between 100,000 years ago and 30,000 years ago. We split from the chimpanzee six million years ago, and you see some changes in tool use with homo erectus, and there’s not that much evidence from the time of homo habilis, I don’t know why. You see some evidence of changes in tool use, slightly more sophisticated, over millions of years. And then, suddenly, after homo sapiens, approximately 60,000 years ago, you see this cultural explosion. Just the ability to teach and learn from each other meant that the skills and discoveries and innovations of the most intelligent group members would then quickly be passed on to other group members. And each generation could learn from the insights of previous generations and build up on those insights. 

So are these two books compatible?

It’s a very difficult thing to try to understand how evolution could have given us what we have. How can we ever get an answer to it? These are just two theories. There is a lot of overlap and they complement each other in a lot of ways. They both recognise the importance of language. Tomasello is saying that a simpler form of social learning exists, that might have become transformed into the kind of social learning that we have, where we can actually truly imitate. He argues that this emerged out of our innate desire to engage with others about the world around us. And from developmental psychology there’s lots of evidence of an infant’s innate desire to engage emotionally with other human beings, which brings me on to my next book, which looks at it from the ontogenetic line of development.