Human nature obsesses us, and has always done so. We know about our animal constitutions, in immense scientific and medical detail. But our psychologies are more elusive. We relentlessly interpret ourselves. We are complex, and can surprise each other and ourselves.
We ask whether it is in human nature to be rational or emotional, selfish or altruistic, short-sighted or prudent, aggressive, pacific, promiscuous, monogamous, murderous or moral, and even after years of experience, some say one and some say the other.
If years of studying history in the library or with anthropologists in the field do not throw up stable answers to these old questions, can experimental methods and science do any better? Sciences, or supposed sciences, are certainly eager to help. Evolutionary psychologists speculate about our hominid ancestors in their Pleistocene environment, while primatologists try to pick up clues about what we are like by looking at chimpanzees and bonobos. Experimental economists have people playing games for pennies, while neurophysiologists interrogate brain scans and social psychologists scatter questionnaires across the world wide web.
Our theories about our selves matter. If I believe that everyone is ultimately selfish, I will conduct my life differently, and may myself become selfish, untrusting and untrustworthy, and other people may follow suit. If I believe that our genes are our fate and that culture does not matter, I will not willingly pay taxes for schools or care what my children watch on television. A mistaken view of human nature may be the beginning of a downward spiral. So not only are these questions interesting in themselves, but they have a direct practical importance.
Simon Blackburn, What Do We Really Know?, s. 17-18.