Barbara King has some interesting things to say when reviewing Michael Corballis book, The Recursive Mind. (here)

Here is her description the situation:

“Astonishing animals show up everywhere these days. Cooperative apes, grief-stricken elephants, empathetic cats and dogs crowd our bookshop shelves. It’s all the rage to plumb the cognitive and emotional depths of the animal world, rejecting sceptics’ sneers of “anthropomorphism” to insist that we’re finally coming to see animals for who they really are: not so different from us. Pushing against this tide of animal awe is a competing cultural trope, the relentless seeking of human superiority.”

She says that Corballis believes that humans uniquely have language, thought and civilization, which is due to having mental time travel and theory of mind, which in turn is due to having recursion. Well, here we go again with Chomsky’s uniquely human key, recursion.

Corballis is also a co-author with Suddendorf of a 1997 paper on mental time travel which makes a similar argument. “This article contains the argument that the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals. Mental time travel comprises the mental reconstruction of personal events from the past (episodic memory) and the mental construction of possible events in the future. It is not an isolated module, but depends on the sophistication of other cognitive capacities, including self-awareness, meta-representation, mental attribution, understanding the perception- knowledge relationship, and dissociation of imagined mental states from one’s present mental state. These capacities are also important aspects of so-called “theory of mind”, and they appear to mature in children at around age four. Furthermore, mental time travel is generative, involving the combination and recombination of familiar elements, and in this respect may have been a precursor to language. Current evidence, although indirect or based on anecdote rather than on systematic study, suggests that nonhuman animals, including the great apes, are confined to a “present” that is limited by their current drive states. In contrast, mental time travel by humans is relatively unconstrained, and allows a more rapid and flexible adaptation to complex, changing environments than is afforded by instincts or conventional learning. Past and future events loom large in much of human thinking, giving rise to cultural, religious, and scientific concepts about origins, destiny, and time itself.” So all the animal studies between 1997 and 2013 have not had any effect on Corballis.

But Corballis does seem to be aware of many relevant animal studies, even contributing to them, and so it is surprising that he would take this outlook. But for some, and Corballis may be one, it seems there is a real need to find a single, significant difference between humans and other animals. Why? I assume it is because they cannot imagine an alternative.

As I have said in previous posts. We are unique but all species are unique. We are not uniquely unique. We are unique in the same way other animals are. We have a little more of this and a little less of that, a different pattern to the mix. But we are basically very similar to other mammals. We are very unlikely to have some characteristic with no other animal having anything similar. The mammals are different from each other but metaphorically they are painted with the same palette. A few million year’s ago there was no difference at all between us and chimps, we were one species. Our paths diverged slightly and so we became a little different and then a little more. But we are still, some millions of years on, very similar to chimps anatomically, genetically, developmentally. But definitely we are not similar culturally.

But when we look at the chimp in the jungle and the astronaut traveling to the moon there is a world of difference. It is this difference that drives people to look for some important significant ability that separates us from the chimp. They look for a different physical characteristic or ability. But the big difference between us and the chimp is cultural not biological.

Cultural evolution was very distinct from biological evolution. It is exponential. Its growth feeds more growth. Suppose we start with some stones used as tools (chimps also use stones). But after a while we start fashioning their shape a bit. Sometime later we get a bit better at fashioning and develop a skill at knapping. Slowly, but at an increasing pace, we learn to make really great stone tools. The same would be true of language. We start as chimps do with communication of a limited kind: a few calls and cries that can be sequenced to a small extent and a number of gestures. We can build on this slowly, very slowly at first but with increasing speed. We end up with a primitive language. We start taking advantage of fires when they occur naturally, then we try to keep and manage them, then make them from scratch whenever we want a fire. Every step in the accumulation of culture is faster than the one before. The culture force becomes enormous and eventually we are changing our way of living constantly. Each innovator could have said, like Newton, “If I have seen farther it is by standing on the shoulders of giants”.

How much does it take for a species that is capable of cultural transmission (as chimp and humans both are) to become two species, one with very little culture and the other with a growing and finally exploding culture. It could be as little as a slightly different niche with slightly different problems and opportunities. Some of our joint ancestors stepped onto one path and some on to another. Of course there was biological evolution in humans but it appears to be mostly driven by cultural evolution rather than the other way around.

As an example of how this works look at the effect of population. Human population has been growing since the start of agriculture in an exponential fashion. As the growers of food can produce more than their family needs, they can have more children and so can others who are fed with the surplus. As long as there is land, we have more food – more people – more farms – more food in an ever increasing spiral. The amount of innovation depends on the population density (or, more likely, the number of people that an average person has contact with in some fashion). So cities are more innovating than the agricultural countryside and cities have been growing in number and size at an ever increasing rate. Soon more than half of all humans will live in large cities. The contact between people is also increasing with travel, writing, electronic communications and so on. So one exponential growth is the basis of another exponential growth and that is the basis of yet another. As far as cultural evolution is concerned it is not just growing at an exponential rate but the rate itself is growing.

The point I am making is that a small, almost immeasurable, difference in the amount of cultural change accumulated in a generation between the group that would become humans and the group that would become chimps, can over a few million years result in the sort of differences we see now. Humans could have come from the individuals with the slightly harder environment or something like that. There need be no biological difference at first. Later there will be some genetic change that is driven by cultural change, of course. For example, once some sort of pre-language culturally acquired vocal communication starts to be an important advantage then there is going to be a selective pressure for changes to the vocal apparatus, hearing and the brain to make that communication more fixed and efficient in the population. It has become a situation where the genetic change follows the cultural one.

We do not need to look for the source of our unusual life style and achievements in some special facility that we have and other animals do not. It is more likely that our history started with some small quirk of fate like which side of the Rift Valley was our home. Our biological changes are mostly caused by our cultural changes and need not actually be very large. There is no need to look for some very significant physical difference, like a brain that can uniquely do recursion, to explain our present situation.