Pigeons ‘not so bird-brained’
Pigeons can recognize individual human faces and the expression on them, showing that they are far more intelligent than hitherto suspected, a psychologist said yesterday. ‘We showed the birds black-and-white photographs of four people, each exhibiting four emotions – happiness, anger, surprised and disgust, ‘said Prof Edward Wassermann of the University of Iowa.
In each experiment, a bird was shown the picture, and was taught to reply by pecking at one of four keys. ‘After being rewarded with pinches of grain for each correct answer, they all learned to identify the person and the emotion correctly,’ he said. If they made a wrong identification, they were ‘punished’ by not being given the grain. ‘To make it more difficult, the faces were photographed without any special distinguishing features such as clothing or jewellery.’
The people pictured were all about the same age; two women, one of each fair-haired, the other dark-haired. Their slightly exaggerated expressions showed happiness, with broad grins; anger, with furious, threatening scowls; surprise, with wide open mouths and staring eyes, and disgust, with twisted lips and screwed-up eyes. After each bird had been shown an expression on one face, it was shown another photograph and ‘asked’ whether the new face had the same expression. Once the birds had recognized the expressions, they never mistook them.
‘The experiments show that pigeons are more intelligent than any animals except for dogs and primates,’ Prof Wassermann said. ‘We suspected this since, in the countryside, they can tell the difference between a man with a shotgun and a man carrying a walking stick. They showed the same amount of intelligence as human babies, who are not born with the ability to recognize the expressions on people’s faces, but have to be taught it. Charles Darwin speculated in the last century that some birds might have this ability, but it’s amazing to have it proved.
The Daily Telegraph (BrE)