Thursday, 23 April 2009

Darwin and his emotions

Amongst all the talk of evolution and this year’s anniversary of On the Origin of the Species, it is easy to forget Darwin's contributions to other fields of science.

This week, the great man’s contribution to psychology and neuroscience was highlighted at a discussion meeting at the Royal Society in London, and in a feature article published in Wellcome History.

Dr Paul Ekman from the University of California, San Francisco, opened the discussion meeting on ‘The Computation of Emotions in Man and Machines’ with a presentation on Darwin’s forecasts about facial expressions, as outlined in his 1872 book, The Expression of Emotion in Man and Animals.

It was perhaps the first scientific book to make extensive use of photographs. Darwin focused on the face, rightly recognising it as one of the richest sources of emotional information a scientist can study. And it paid off. Ekman remarked how Darwin’s forecasts about the nature of facial expression of emotion, and emotion itself, were nearly all correct.

There is increasing evidence from brain research to support Darwin’s view that we consider each emotion as a separate, discrete entity. He also proposed, rightly, that there are a ‘universals’ in facial expression of emotions that all humans use. And he recognised that emotions are not unique to humans, making him something of a hero of the animal rights movement of the time.

The blush, however, was one emotion that Darwin mused may be exclusive to humans. He dedicated a whole chapter of The Expression of Emotion to the emotion, wondering whether it occurs in all human groups and in different species.

In Wellcome History, Professor Ray Crozier writes, “His subsequent research on blushing exemplifies the relentless collection of evidence that characterised his scientific work, drawing upon an extensive network of correspondents… to establish whether people of all skin colours blush and whether young children do so, and… whether the blind and ‘idiots’ do.”

Darwin thought the blush emphasised self-attention (“it is the thinking of what others think of us which excites a blush”). He related it to shyness, shame and modesty, all of which involve self-attention, but not necessarily a lack of moral sense, as other scientists argued.

Modern research has built on this. Psychologists, for instance, have found that people tend to judge an individual less negatively if a blush accompanies some wrongdoing (a finding which was also highlighted at the Royal Society meeting).

As Crozier puts it, Darwin “anticipated contemporary theorising” on the blush, which relate to self-consciousness and psychological states, such as embarrassment, that involve our concern with how we appear to others.

“Darwin brought to many scientific fields eagerness to ask difficult questions and the resilience to sustain empirical projects lasting for years. Even though technical resources necessary for research were not yet in place… his observations have stood the test of time.”

Image: Chimpanzee looking tired and sulky. Drawn from life by Mr. Wood. From The expression of the emotions in man and animals
Credit: Wellcome Library, London

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