Emotions Part1

Part 1 Why do we have them?

In 1952 McClean proposed a model of the brain as consisting of 3 parts; the stem, the limbic brain, and the neocortex. Brain physiology certainly shows distinct structures within the brain. He advocated the theory that as the brain evolved it did so, not by fluid wholescale changes, but, by adding on modules (which gradually became bigger and more complex). The original function of the stem brain did not change, but the extra functional capabilities of the limbic brain were added and then later the neocortex (where higher processing and consciousness occur) was added.

In 1980 Plutchik posited that basic emotions were rooted in the limbic brain – fear, disgust, anger – and that higher emotions springing from our social interactions were rooted in the neocortex – guilt, love, sympathy.

In 1990 Nesse furthered these models by using the language of game theory. He assigned emotions to the possible emotional states produced by the iterative prisoner's dilemma:

When both players cooperate they feel friendship, love, loyalty, obligation, pride.

When both players defect they feel hatred and rejection.

When one cooperates the cooperator feels anger and the defector feels guilt.

If someone looks happy and friendly you can predict that they are probably a cooperator. If they look angry/guilty then they are probably a defector and you should avoid cooperation in a social contract with them.

Another useful theory when considering emotions is that they may limit violence in squabbles. If there is a disagreement between obviously physically mismatched people then logically the weaker should simply concede. However, by displaying emotion like anger the weaker one signals that they may not act rationally and so the stronger should think twice about escalating a conflict. Fans of Dr Strangelove will recognise this as being analogous to the doomsday device; protection by Mutually Assured Destruction.

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