Matt Ridley: Nature via Nurture

Reviewed by STAN PINNEGAR

Science writer Matt Ridley is the best-selling author of Genome and, as with that book, when we turn the leaves of Nature via Nurture, we open a door to more questions and debate than science can yet answer.

Beliefs held dear through the ages are quashed or hung out for more serious thought.

When Darwin demolished the assumption that humans have peculiarities that set us apart from other animals, we began to realise (at least those who believed him) that the differences were not quite so inarguable but were merely a matter of degree.

Ridley points out that St Augustine said only humans had sex for pleasure, yet we now know that chimpanzees, especially bonobos, have sex to celebrate a good meal, to end an argument or cement a friendship.

Some scientists, he says, believe that chimpanzees do not have a theory of mind, that is, they cannot imagine what another chimp is thinking. But studies show ambiguity.

Chimps, we are told, regularly engage in deception. A baby chimp, for example, pretended he was being attacked by an adolescent so his mother would let him suckle her.

Baboons, the author tells us, have performed well enough at computer discrimination tasks to show they are capable of abstract reasoning.

Infanticide is common among many primates. A bachelor male gorilla infiltrates a harem, grabs a baby and kills it. This causes the mother to grieve and stop lactating, which brings her back into oestrus.

Then she is persuaded she needs a new harem master who is more able to protect her babies. And who better to choose than the raider?

But female chimpanzees have a counter-strategy, the book tells us. They share their sexual favours around so that any raider would be careful not to kill a baby lest he was killing his own offspring.

But the book offers much more than an insight into the mating habits of primates. It takes, for example, an interesting look at coincidences.

In the chapter The Madness of Causes we learn about such mental illnesses as bipolar disorder and, in Blame Mother, schizophrenia.

The author makes the sobering point that heritability of schizophrenia is high in Western society, roughly 80 per cent, or about the same as body weight and much more than personality. And did you know that a mouse has 1036 olfactory sensors in its nose?

Human beings have only 347 intact olfactory genes - though we do have a lot of rusting hulks of old genes (pseudogenes).

By the time the chapter Redesigning People is reached, the reader's appetite is well and truly whetted for more information on what makes us and the rest of the world tick and the book ends all too quickly.

I still don't know what my dog dreams about nor where he goes to when he sits for so long silent and still in the garden on a pleasant summer evening.

But I now know that he goes somewhere.

* Fourth Estate, London, a division of HarperCollins, $69.99