2  Emotions in an evolutionary context

Like other living things, people are the products of millions of years of evolution. An evolutionary approach thus has the potential to provide a number of important insights into the nature and function of emotions and emotional systems, and can enhance our understanding of what constitutes mental health and ill-health more broadly (Marks and Nesse, 1994; Nesse, 2006).

The evolutionary approach postulates that many of our physical, mental, social, emotional and spiritual characteristics and tendencies exist because they were useful or even essential in enabling our ancestors to survive and reproduce more successfully than their competitors. In other words, such characteristics and tendencies were adaptive; helping us to adapt to survive.

It is important to realise that evolutionary processes build on, or modify, what is already there – they cannot start from scratch. The changes brought about by evolution are a bit like remodelling your home over time. You may have installed electricity in your ancient cottage, but the low beam at the bottom of the stairs is part of the core structure of the building and cannot be removed. So, though you need to bend a bit to avoid banging your head on it, you just have to live with it. In the same way, we retain a great deal of the machinery and modes of operation of many of our ancestors. For instance, parts of our brain, particularly those parts associated with emotions have a similar structure and organisation to that of many other animals. We will explore this later on in the section.