How Valid Is Evolutionary Psychology?

From Steve Taylor Ph.D. on Psychology Today.com (Dec. 9, 2014):

Why do we find natural scenes like green fields, trees, and rivers beautiful? Why do people have an urge to gain wealth and power? Why do human beings fight wars? Why are human beings creative?

According to evolutionary psychology, the answers to these questions are linked to survival and reproduction. Evolutionary psychology explains present-day human traits and characteristics in terms of the survival value they possessed for our ancestors. These traits have survived because the genes they are linked to were ‘selected’ and have remained part of our genetic heritage. So in terms of the above examples, we find natural scenes attractive because for our ancestors they represented survival—lush vegetation, trees laden with fruits and nuts, rivers. People have an urge to gain wealth and power because, in prehistoric times, they enhanced their chances of survival and increased their reproductive possibilities. The instinct to wage war is so strong because prehistoric tribes of genetically similar people were in constant competition for resources with other groups. The creative instinct can also be seen as a way of increasing our reproductive possibilities—successful creativity increases our status and so makes us more attractive to potential mates.

It’s clear from these explanations (all of which have been put forward by evolutionary psychologists) that evolutionary psychology has a great deal of explanatory power—seldom has such a simple idea been used to explain such a wide variety of human behavior. This is probably the reason why the theory has become very popular, especially in the media and amongst non-scientists. As human beings, we have a strong need for explanation, to make sense of our behaviour and of the world around us. (This is part of the reason why religions are appealing to many people too.) However, the negative side of this is that, when theories do have explanatory power, we tend to become over-enthusiastic about them, and to over-estimate their validity. And I think this is the case with evolutionary psychology. Seldom has a theory gained such widespread support whilst being based on such shaky foundations.

Having said that, my problem with evolutionary psychology isn't so much with the theory itself, but with how it has been used to justify a particular view of human nature. After all, it makes sense to assume that we have inherited some behavioural tendencies from our ancestors, that some of the instincts we carry originated millions of years ago. As I suggest later, it might be possible to formulate an alternative interpretation of evolutionary psychology that doesn't make such grandiose claims, and is more in line with anthropological evidence. [read more]