Why do we have moods?

In our society, many see being moody as a problem. This is true to some extent, but moods are generally beneficial. For example, consider two hunter-gatherers, Alice and Bob. They live in a territory where the main source of food is berries growing under bushes. Some bushes have no berries, whereas others are full of them. Gathering them is a tiring activity, for one has to walk close to a bush and lift some of its leaves to know whether it contains any berry. Alice is unable to feel any mood, whereas Bob can. Who do you think is a better gatherer, all other things being equal?

The answer is Bob, because he is more likely to check the bushes with berries and to not check those without berries. Why?

Well, Alice does not feel any mood, so she would tend to sample every bush she walks by – an inefficient method. Instead, Bob would check the first bush, then the second one, then he might become discouraged (a mood), and he would walk for a bit before bending forward to check the bush next to him. Once he finds some berries, he gets excited (another mood) and checks all the bushes nearby. This is advantageous because, in nature, resources tend to cluster together. If a bush is particularly fruitful, the chances are that the ones around it are, because they grow on the same fertile soil.

Moods are tools to allow us to adapt to environments with clustered resources.

(References: “Mood as Extrapolation Engine: Using Emotions to Generate Momentum”,  by Tiago Forte, 2017, referencing “Mood as Representation of Momentum”, by Eldar E., Rutledge R. B., Dolan R. J., and Niv Y., 2016.)

End of the excerpt

This is an excerpt from my book “The Control Heuristic​: Explaining Irrational Behavior and Behavioral Change”. You can purchase the book here.