Sphex Reply to on 30 August 2010
|Human anatomy applies to all peoples of the world. Why should the anatomy of the mind be any different? Every living human has the same sort of heart. Every thinking, feeling, loving, caring, hating, judging, lusting person has the same sort of brain. Being vastly more complex, the brain has more scope for individual variation while remaining a functioning organ, but still there is a huge overlap between the brains of any two people on the planet, and so also between the behaviours those brains generate. Our everyday behaviour is rooted in a biology we all share, and evolutionary psychology is its scientific study. In this classic work, Robert Wright explores this new science and shows how it leads to a deeper understanding of ourselves and our social world.
We all have intuitive ideas about why we are the way we are: nationality, colour, parental influence, peer pressure, culture, and so on, all partly determine our identity. One fact beyond intuition, however, is the rather longer timescale over which evolution has shaped both our bodies and our brains. Just as the circumstances of a childhood can affect a whole life, so too does the ancestral environment we grew up in as a species continue to make itself felt. That it does so in ways which are largely hidden from conscious view only serves to point up the importance of evolutionary psychology. We should not make the mistake of comparing the sparsely populated open savannah with the bustling cities many of us now live in and concluding that our evolutionary history has no relevance. We are remarkably flexible in many ways, but we are most certainly not blank slates. Human nature is a collaborative project in which we are often the junior partners who cannot edit the words of long-dead senior scriptwriters.
There are many adaptations that have outlived their logic, but which still affect our behaviour. An example is the sweet tooth. "Our fondness for sweetness was designed for an environment in which fruit existed but candy didn't." (Any sensible person reading this will immediately provide their own scare quotes around that word "designed", as Wright himself does elsewhere. Natural selection works as if "it were consciously designing organisms" to behave in a certain way. There is no designer, of course, nor any plan or purpose.) We may want to be slim but natural selection "demands" that we cram in as many calories as we can to stave off the Malthusian extinction that was a constant threat to our ancestors.
Personal happiness is often taken to be a natural desire. Its pursuit has even been written into a political constitution. However, natural selection doesn't "want" us to be happy, it "wants" us to be genetically prolific, and those two goals are uncomfortable bedfellows. We are each under the hypnotic spell of a single truth: "My hereditary material is the most important material on earth; its survival justifies your frustration, pain, even death." Fortunately for us lumbering collections of replicators, we share some of this precious material with others, so this bleak doctrine of the selfish gene is also capable of generating cooperative behaviour, such as reciprocal altruism. The simple strategy of tit for tat - "do unto others as they've done unto you" - models how this could have evolved.
Rigid behavioural responses have a limited usefulness, especially in a social environment that can change more rapidly than the physical one. People don't always repay kindness with kindness, but sometimes lie, cheat or steal - and prosper as a result. Remember, if you can get more of your genes into the next generation by behaving badly, that's what natural selection "wants" you to do. Those on the receiving end have other ideas, of course, as do their genes, and natural selection will "help" them too if they can come up with a way of reducing the payoff from lying, cheating and stealing, that is, if they can modify the social environment so that such behaviours are discouraged. Hence feelings like guilt evolved, perhaps first gaining a foothold through kin selection, which encourages us to look out for siblings and to feel bad if we don't.
A family of related individuals is part of a broader society, and both are held together by varying amounts of the various "ingredients of morality, from empathy to guilt". Evolutionary psychology explains "the adaptive value of a malleable conscience" and points to its "firm genetic basis". The seeming paradox of flexibility built on fixed genetic foundations can be dissolved by thinking of human nature as consisting "of knobs and of mechanisms for tuning the knobs", where the tuning depends on the particular social environment encountered.
Paradox is one thing, controversy another. Given the long struggle to achieve political and legal equality between men and women (rights still not recognized in some parts of the world), it's hardly surprising that some took umbrage at the idea that, for example, "male and female jealousy should differ". We all accept there are obvious physical differences between men and women, but there is also an equally obvious behavioural difference: while men "can reproduce hundreds of times a year, assuming they can persuade enough women to cooperate", women "can't reproduce more often than once a year". When it comes to maximizing their genetic legacy, men and women have different agendas, not as a result of culture or conditioning but because of "the scarceness of eggs relative to sperm". Much of human sexual psychology flows from this biological fact, including the Darwinian perils of cuckoldry for a man and desertion for a woman.
"The new Darwinian synthesis is, like quantum physics or molecular biology, a body of scientific theory and fact; but, unlike them, it is also a way of seeing everyday life." This is a source of excitement to some and anxiety to others. In intellectual terms, it is reassuring that Wright is quite happy to describe some elements of the theory as speculative, supported only by circumstantial evidence. In terms of social policy, we should not despair that human nature relies in part on largely fixed and selfish genes, because "the most radical differences among people are the ones most likely to be traceable to environment" - and this is something we can influence.
Religion has long monopolized ethics, with disastrous results. Even one small sect of one religion after five hundred years cannot decide whether women bishops are a good or a bad thing, and yet they still claim to provide moral leadership. The scientific study of our moral nature holds out far more hope, both in practical terms of informing policy but also as an awe-inspiring insight into the "deeper unity within the species". Perhaps most hopeful of all, and most surprising to find in a book of science, is one of Robert Wright's conclusions, "that the new paradigm will tend to lead the thinking person toward love and away from hate".