In Chapter 7, we define the biological school of thought in personality psychology. Compared to most of the other schools that we have covered so far, the biological school of thought has been relatively slow to develop. However, we shall learn that the advent of evolutionary psychology (drawing upon Charles Darwin’s theory of natural selection) has been responsible for a dramatic increase in biologically orientated perspectives within personality psychology. We will compare and contrast the perspectives within this school; and we will offer a critique of the biological school in general. Finally, we provide a prelude to Chapter 8 (Concluding Thoughts on Personality Psychology).