Evolutionary Psychology

Evolutionary Psychology is simply the application of the theory of evolution to personality and behaviour. Firstly, there are multiple theories of personality and behaviour. The brain is very complex and the functionality of the brain is not fully understood. Some theories of personality seem to explain behaviour better than other in certain situations. Hence we can pick and choose whatever theory of personality seems to be the most appropriate at any particular time. As I explained in an earlier blog even the definition of personality is somewhat difficult. We often describe personality in terms of behaviour. If someone acts aggressively we might say they have an aggressive personality, the problem arises then if that same person acts in a co-operative manner; has their personality changed?

The theory of evolution, or natural selection, states that not all individuals in any species are identical; and those individuals who are more suited to their environment will do better and reproduce more often. Hence, successful genes are transmitted to the next generation. Over time, successive generations will become more adapted to their environment. Note, evolution relies upon reproduction not survival; it is quite possible that very very risky behaviour that might result is death could lead to more reproduction opportunities. The Black Widow spider is called the black widow because the female spider eats the male after mating.

Initially, the theory of evolution focused on the physical properties of species. Charles Darwin measured the differences in the size, speed, colour and diet of the closely related species to show how different species were adapted to their environment. However, psychologists wondered if behaviour and personality could also be a result of evolution. Once psychologists began to consider personality as a result of evolution the supportive examples began to come quickly and easily. As an example, many animals rely on camouflage to hide from predators; however this camouflage only works if the animal remains still and remains in an area that supports the camouflage. A green tree frog blends into green foliage; however the same frog on a sandy beach would stand out and be an easy meal for some predator.

Psychologists then began to wonder if human behaviour was also influenced by evolution and if behaviour could be in inherited. Some of the findings about the inheritability of behaviour are a little controversial and require more time than available in this blog to explain. However, study of identical twins have shown that many attitudes can be inherited including; belief in religion, support for political parties, even crime appears to be inherited. The gold standard of this type of research is to find identical twins raised apart and then to measure their attitudes and behaviour, of course identical twins raised apart is incredibly rare. However, where identical twins are raised apart the similarity in behaviour, attitudes and life styles is remarkable. Hence, there is very good scientific evidence that much of our behaviour is encoded in our genes.

The question is how does evolutionary psychology effect our health and fitness outcomes? Also if behaviour is encoded into people genes are people really able to change? In the next few blogs I will attempt to answer these questions in simple, not to scientific language.