Question: How does emotions happen? and why do we have emotions?

Carolyn McGettigan answered on 24 Mar 2010:

Great questions. Emotions can emerge through a number of different mechanisms. Some parts of the brain have been linked to emotional responses, for example the amygdala for fear, and the insula for disgust. There are also lots of hormones and other chemicals floating around in our bodies, and these can influence mood and behaviour. There are some links between the levels of some of these chemicals in the brain – for example dopamine and serotonin – and conditions like clinical depression.

A way to think about why we have emotions is to consider an animal’s very basic reactions to events in the world. For example, anger and aggression could be used in sexual competition for mates. Fear is a helpful response if there is a threat in the environment – we get that rush of adrenalin and the ‘fight or flight’ response that could prompt us to run from attack or prepare us to defend/fight. Disgust at something horrible, like the smell of rotten food, warns us that the food could be poisonous. Then there are things like happiness. There is evidence that non-human primates like chimps exhibit laughter. Like us, these are very social animals and laughter and happiness are often emotions that we experience with other people – so, maybe this emotion has emerged for ‘social cohesion’, keeping the social group together.

If we think about more complex emotions, like jealousy, envy, regret…then I suspect these are more particular to humans, and are as a consequence of our brains’ further development beyond that in other primates. It’s true that sometimes these emotions can seem like they complicate life and weigh us down, but I think they are a consequence of our ability as humans to recognise mental states and intentions in others, which on the plus side also supports the rewarding aspects of emotional relationships between humans.