2.5  The value of negative and positive moods and emotions

An evolutionary approach allows us to be open to the idea that negative as well as positive emotions have value. This is obvious for some negative emotions such as fear and anxiety; for example, in the context of escaping from a bear. It is not so obvious for sadness, or worry (a form of fear and anxiety about the future).

It has been suggested that sadness can be useful in some circumstances and hence have an ‘adaptive’ function. For example, it might make individuals reconsider problems such as failed goals, and lead them to abandon unhelpful ways of behaving or of doing things (e.g. Oatley and Johnson-Laird, 1987). To use a physical analogy, pain is unpleasant and aversive but is considered adaptive as it can benefit an injured individual by preventing further harm or damage.

That low mood can indeed be useful is shown in a series of studies carried out by the psychologist Joseph Forgas and his team at the University of New South Wales. They found that, while performing a task, people in whom a sad mood had been induced paid more attention to details, were less gullible, less likely to make errors of judgment, and were more likely to come up with high-quality, persuasive arguments than people in whom a good mood had been induced (Forgas, 2009). Good or bad mood can be induced in people by, for instance, showing them happy or sad images or films.

Worry, too, can be useful. Psychologist Graham Davey of the University of Sussex found that although worrying sometimes made things worse for participants in his study, it often motivated them to take action and resolve problems and this in turn reduced anxiety (Davey, 1994). Similarly, McCaul et al. (2007) found that cigarette smokers were more inclined to stop smoking if worried about the risks of smoking. Overall, such findings suggest that mild to moderate levels of worry can be beneficial, motivating people to put in the bit of extra effort and attention needed to make a success of their endeavours.

Conversely, an evolutionary stance allows for the possibility that emotions we consider desirable may not be universally (i.e. in all circumstances) ‘good’ or appropriate. While there is evidence that positive mood facilitates creativity, flexibility and cooperation there is also evidence that misplaced optimism can lead to rash decisions and risk-taking (Alloy and Abramson, 1979).

Aversion and approach are facilitated by different emotions. Low and high mood may be useful in certain situations but may be very unhelpful in others.