Brains and behaviour
Can evolutionary ideas explain human behaviour?
Darwinian views of evolution imply that all aspects of the biology of organisms must be adaptive – providing some kind of selective advantage – otherwise they could not have evolved. Applied to humans and their behaviour, this is known as evolutionary psychology.
The case of humans is special for several reasons. The ﬁrst is the radical change that has taken place in the way we live over the past few thousand years – a blink of an eye in evolutionary terms. Then there is the power of our brain, about which we know relatively little. Finally, there is the potential for cultural evolution (see ‘Cultural evolution’).
Evolutionary psychologists suggest that humans are adapted to survival in a harsh, Stone Age world. Our brains have given us such a competitive edge that we have spread across the globe and developed art, culture and technology at remarkable speed, but deep down we are driven by the same survival instincts we had in those early days on the African savannah.
The selective pressures shaping our vision, hearing and memory are relatively non-controversial. For example, we remember fearful incidents better than run-of-the-mill events – which would help us avoid danger.
But what about, say, our reaction to strangers? Are we programmed by evolution to ﬁnd them threatening? Or is this a reaction driven by the nature of modern society?
Could some skills simply be by-products of an adaptive trait? Chinese people excel at table tennis, but no one seriously believes that table tennis ability promoted survival in the Pleistocene or that there are genes for table tennis.
So evolutionary thinking can undoubtedly help us understand how the human mind has developed. But although it can come up with plausible explanations for human physiology or biology, these are hard to test experimentally. And, of course, the links between genes and human behaviour are rarely straightforward.Lead image:
Steve Hall/Flickr CC BY NC ND
Questions for discussion
- Do you think human behaviour can be explained in terms of adaptions for life in the Stone Age?