Last August I wrote about a study of ice hockey players, which revealed that the larger the width-to-height ratio of a player’s face, the greater the aggression of that individual. I referred to it then as 'the new phrenology', but as Roger Highfield correctly dubs it in this week's New Scientist, it is actually 'the new physiognomy', the inference of personality from facial characteristics.
The basic message remains as before: people with wide faces are 'bad uns'. In addition, however, you might also be able to infer trust-worthiness and dominance from facial characteristics, as the diagram here illustrates. (The diagram, however, appears to be a glabrous cross-section through the hairiness dimension; how does facial-hair affect our impressions of trust-worthiness and dominance? Was I right to like Mr Beardy?)
This type of study, of course, is the result of research by psychologists. All behaviour is explicable, post-hoc, by psychologists, and Roger Highfield's article contains an absolute classic of the genre. It is suggested that "our prejudices about faces turn into self-fulfilling prophecies...Our expectations can lead us to influence people to behave in ways that confirm those expectations: consistently treat someone as untrustworthy and they end up behaving that way." It is then suggested that the effect also works the other way round, that there is also a self-defeating prophecy effect, particularly for those who look cute, in which "a man with a baby face strives to confound expectations and ends up overcompensating."
As I understand it, if the behaviour of an individual or group of individuals is contrary to some effect postulated by a psychologist, the psychologist then explains that behaviour by inventing an inverse effect. It's a simple trick, but if you play it really well, you could ultimately end up reaching the zenith of your profession, analysing contestants on Big Brother.