Professor Robin Dunbar became a biologist by accident. He is now, aged 55, one of the most respected evolutionary psychologists in Britain, and heads the evolutionary psychology and behavioural ecology research group at Liverpool University. But he had no childhood passion for animals - "Growing up in east Africa, our family had absolutely no interest in wildlife unless it was at the end of a barrel of a gun" - or science for that matter. As he tells it, he discovered science only because of his incompetence at Latin.
At grammar school in Northamptonshire, he took a Latin A-level (with history and philosophy) but found the only way he could pass the exam was by memorising English translations of the set books. "I learnt them all verbatim, in about two months. You could have given me a line of Latin, and I could recite six pages of English." It was a feat that deserved some academic reward, and he duly got to Oxford determined to avoid the subject. He ended up reading psychology and physiology, as well as philosophy; gradually finding the first of those more relevant and interesting.
At Oxford, he was taught by Nico Tinbergen and his young assistant, another man who had grown up in east Africa, Richard Dawkins. Tinbergen shared a Nobel Prize with Konrad Lorenz for the essential insight that animals have innate, inherited patterns of behaviour, which have been shaped by natural selection just as much as their bodies have been. Dunbar has worked all his professional life in this area, studying animal and human behaviour in search of the rules that guide us. He doesn't hesitate to analyse purely cultural phenomena, such as Shakespeare's plays, in the light of biological principles. This is not so much because principles underlying biology predict what will happen, he says, but because by looking closely at what actually happens, we can work out which principles are being applied in any given case.
"The world is run by a handful of very simple principles but that doesn't mean that the behaviour you see is simple: when you apply these simple principles to a complex world, the costs and benefits of different strategies differ according to life stage and social position." We settle for what we can get, he says, and the really interesting judgments, for his group, are the ones that tell us what we can get and should settle for. He and his team read thousands of lonely hearts ads, for example, to find out what men think women want, and vice versa.
For a woman to be attractive, it is enough for her to say, or suggest, that she is young and good-looking, he says. For a man to be attractive demands on more complicated factors. Essentially, women who want a long-term relationship are looking for men who will make successful grandfathers (not just good fathers: it is no use having lots of children if they do not have children in their turn). That looks simple enough. Women, it turns out, use three or four measures for good mates because they want so many different things from a father. This means the results vary hugely between cultures, even though the underlying mechanisms of judgement are, he believes, universal and genetically fixed. If you look back at Victorian ads, you see huge emphasis on wealth and status; in those days children of the poor died far more frequently than those of the rich. This is still true of personal ads in Boer language papers in South Africa, where it is common, he says, for women to advertise for a husband "with his own tractor" because that shows he owns enough land to feed a family.
"But in the developed world, there has been a big switch to social skills, and good parenting skills." This perhaps explains the enthusiasm for a "GSOH" in the ads. "It's very clear that males in America haven't caught up with this and are still hammering wealth and resources in their advertisements," says Dunbar.
The lonely hearts are not peripheral to biology, in his view, but the most direct route to the brain that makes us human. When our ancestors came down on to the savannah, they had to form large groups to escape from predators. Social relationships became the key to survival. Our brains have grown because they are what we use to keep track of our fellow primates. That they turned out to be good at science, and other forms of understanding the world, is secondary to the need to flourish in a society of other smart primates, all trying to outmanoeuvre us. That requires us to understand that other people have inner lives and, even, ideas about our own inner lives.
No wonder we need crumpled and complicated frontal lobes to consider them and long, playful childhoods in which to learn the rules of society: "The neocortex doesn't correlate with length of gestation, but with the period of socialisation, between weaning and puberty. That is where it learns the rules and responses in the playground that will see it through its life and learn to make the right judgement."
In all primates there is a close correlation between the size of the neocortex and the size of the groups they naturally form. Dunbar carries this theory further. He believes the relatively large size of human groups was what made language necessary.
In his book Grooming, Gossip, and the Evolution of Language he argued that other primates, living in smaller groups, can maintain their social relationships by picking fleas off each other. "You scratch my back, and I'll scratch yours" is the fundamental law of baboon sociability. But grooming is time-consuming and can only be done in pairs. Humans seem to be adjusted to groups of about 150 people - the largest size in which we feel confident of keeping track of individual personalities and their interactions. To gain this information by grooming would leave no time for eating or sleeping. Language allows us to interact simultaneously with far more fellow primates than we could hope to groom.
What distinguishes humans from all other animals is this ability to pile perspectives together into dizzying insights. This has fascinated Dunbar ever since he read philosophy. He would like to be a novelist. "I say that I became a scientist because it's the only way that I could get published." He did earn his living as a freelance science writer for a couple of years after Thatcherite cuts purged higher education of his job. He went back to working science when the opportunity came and in 1995, when Grooming, Gossip and the Evolution of Language was published, moved to Liverpool, got into Who's Who and, two years later, the British Academy. He has a knack for experiments that make stories: one team of his students sat in the pub opposite Liverpool law courts analysing the way lawyers display their mobile phones as if they are birds displaying their tail feathers; another has been studying the plays of Shakespeare to see which make the greatest demands on our understanding of other people's understandings of characters' inner lives: according to this theory of mind, there ought to be a level of complexity beyond which only Shakespeare could understand what's going on, and possibly only Shakespeare does. This would account for the relative unpopularity of plays such as Titus Andronicus.
His books are not bestsellers. They're too scrupulous for that. This suggests a wider problem with science. The gap between the huge questions science is meant to answer and the grinding tedium of science as taught widens every year. If trends continue, he says, no one will study science in 20 years. The number of students taking up chemistry and biology has declined steadily for 10 years, he says, "and if we hold that decline, both lines will hit zero in 2015". Why? Science is difficult and the collection of data can be boring even at the best of times, "but my impression is that the way in which science is taught becomes increasingly mechanistic, and loses sight of the big questions. There is still a sense that you must read novels to find how the world really is, and how people tick."
The answer, he thinks, is to start with things children have evolved to notice. Why birds make nests, or boys and girls play separately. Once you start from behaviour, your explanations can go down to genes or up to evolutionary theory. Children can be led towards this by experimenting themselves, gathering data and testing hypotheses in ways that would be impossibly expensive in big sciences, such as physics and molecular biology. Only by teaching children how to do science, he says, will they ever come to see the point of doing it - and if they don't, there soon won't be any new scientists in Britain.
A brilliant career
Robin Dunbar was born on June 28 1947 in east Africa. The son of an engineer, he was educated at Magdalen College School in Brackley, Northamptonshire, and Magdalen College, Oxford. He became a scientist "because it was the only way I could get anything published" and has worked on reproductive strategies in baboons, feral goats and homo sapiens. He has been Professor of Evolutionary Psychology at the University of Liverpool since 1994. In 1988 he was elected a fellow of the British Academy, an award made for high scholarly distinction in a branch of the humanities or social sciences.
The Trouble With Science, Robin Dunbar. Faber and Faber, 1996. ISBN: 0571174485
Grooming, Gossip and the Evolution of Language, Robin Dunbar. Faber and Faber, 1996. ISBN: 0571173977
Human Evolutionary Psychology, Louise Barrett, Robin Dunbar and John Lycett. Palgrave, 2001. ISDN: 0333725581
Cousins: Our Primitive Relatives, Robin Dunbar and Louise Barrett. BBC Consumer Publishing (Books), 2000. ISBN: 0563551151