What is the difference between the biological and behavioural psychological approaches?

The biological and behavioural views of psychology allow for two different approaches to studying the subject and often link to the nature-nurture debate.

The biological psychological approach is linked with the nature side of the nature-nurture debate. The approach assumes that all behaviour (whether human or animal) is driven by genetics and a person’s biological / chemical composition. It assumes that the environment cannot change your behaviour and that your actions, decisions and the way you live can be traced back to stemming from your parents, from which you inherited your genes.

In contrast, the behavioural approach assumes that our behaviour is a product of our interaction with the environment. It assumes that as babies we are born as a blank slate and from this moment on are shaped and influenced by the people and environment surrounding us. Hence the approach takes the nurture side of the nature-nurture debate. In contrast to the biological approach, the behavioural approach assumes that our behaviour is determined by the environment in which we find ourselves, for example, we may act differently in front of teachers at school, compared to when we are with our friends.

The two approaches can be investigated by looking at identical twins that have been either raised together or raised apart after being separated at birth.

The biological approach would assume that twins would behave and be exactly the same as each other whether they had been raised together or apart, whereas the behavioural approach would assume that the twins reared apart would behave differently to each other, due to their different surroundings.