The Third Chimpanzee

The Third Chimpazee was the title of a book by by Jared Diamond. That was in the tradition of seeing our continuity with the apes.

Here is a bit from a review of a book by Jeremy Taylor that takes a different tack: recognizing the gulf between us and our closest ape cousins:

Not a Chimp: The Hunt to Find the Genes That Make Us Human is a refreshing defence of human uniqueness. ‘We are a truly exceptional primate with minds that are genuinely discontinuous to other animals’, Jeremy Taylor writes.

The first half of Not a Chimp challenges ‘the basis of a 40-year-old concept of human genetic chimp proximity’. Taylor does admit that ‘over very appreciable lengths of their respective genomes, humans and chimpanzees are very similar indeed’. He writes: ‘This is where the oft-quoted “1.6 per cent that makes us human” comes from. Despite 12million years of evolutionary separation, six million for each species since the split from the common ancestor, we are surprisingly similar in our genes.’

Yet he argues that, despite the very small difference in the gene coding sequence between humans and chimps, some of the important genetic differences are in genes that regulate a whole host of other genes. So a small change can make an immense difference. The genetic difference between us and chimps may be much greater than the 1.6 per cent figure implies, as our uniqueness is based on a powerful network of gene regulation, he argues.

Human development is complicated as the following bit demonstrates:

Taylor shows that many of the overblown claims made by scientists are pounced on by the media. In 2008, the UK’s Channel 5 aired a documentary on Tetsuro Matzuzawa’s chimpanzee research in Japan, which had already drawn newspaper headlines such as ‘Chimp beats college students at math’. One chimpanzee, Ayuma, was able to beat humans at a computer game where the numerals 1 to 9 were flashed up in random patterns on a screen before being replaced by an empty box. The participants then touched the screen to put the numerals in the order they had just been shown.

But does the fact that the chimps did well on this task merit the claims that they have ‘leapfrogged’ us in their mathematical abilities? Of course not. As Taylor points out: ‘This was a test of eidetic – or photographic – memory, not mathematical skills.’ He adds: ‘Tiny children have this skill before it becomes engulfed by language and a genuine symbolic understanding of numerals.’

This is something my husband discovered to his surprise when he was thrashed by a three- and a four-year-old child while playing the ‘Memory Game’, where one has to memorise the location of cards turned upside-down and try to retrieve matching pairs.

The other aspect of humans that makes us unique is our imitation and, consequently, our social learning:

Although the bulk of Not a Chimp focuses on the case for our genetic uniqueness, Taylor does recognise that biology alone cannot explain our exceptional abilities. Like a number of groundbreaking developmental and comparative psychologists, he recognises the powerful role of social learning – such as true imitation – in human development. The difference between emulation (which other animals are clearly capable of) and true imitation ‘is crucial to an understanding of how we, as a species, have amassed such a variety and complexity of material culture’. He writes:

‘Understanding that a demonstrator intends his actions to make something, allied to detailed copying of every move he makes, allied to the reciprocal understanding in the demonstrator’s mind that he knows something you don’t and therefore has to teach you it, produces a potent ratchet effect.’

It looks like I need to put this book on my "to be read" pile.