Brain scan showing the ‘hate circuit’ (source: University College London)

Hate has a physical basis in the brain, according to biologists at University College London.

Reporting in the open-access journal PLoS One, Semir Zeki and John Romaya say that activity in specific areas of the brain correlates with hateful feelings. The two researchers show that the ‘hate circuit’ they have identified shares a part of the grey mass associated with aggression, but at the same time is distinct from those areas related to fear, threat and danger.

The neural circuit studied by Zeki and Romaya includes two distinct structures known as the putamen and insula, which are located in the outer and inner parts of the cerebral cortex. It also involves a section of the frontal cortex thought to be connected with predicting the actions of others. Interesting to note, but maybe not surprising, is that the putamen and insula are also activated by romantic love.

Says Zeki:

“Hate is often considered to be an evil passion that should, in a better world, be tamed, controlled, and eradicated. Yet to the biologist, hate is a passion that is of equal interest to love. Like love, it is often seemingly irrational and can lead individuals to heroic and evil deeds. How can two opposite sentiments lead to the same behaviour?”

Philosophers and others have been discussing this question for centuries if not millennia. Will biology bring us closer to an answer?