THE INFANT laughs and smiles, delighted to play the peek-a-boo game with its surrogate parent. The scene seems all so familiar but for the fact that the infant being filmed is a weeks-old chimpanzee.
Infant chimps smile and cry, pout and fuss much the same as a human baby.
And a scientist at the University of Portsmouth believes the whole gamut of chimpanzee emotions can be understood by learning to read their facial expressions.
Being able to interpret these might not help us understand human babies any better but they might help us discover how the ability to make and read these expressions evolved, stated Prof Kim Bard, professor of cognitive and developmental psychology at Portsmouth.
“Some emotions are really easy to identify,” she told the British Science Association’s annual Festival of Science under way this week in Guildford.
“Signs of distress you can see in chimps just like humans, and chimps just like humans also cry.” The challenge was to read the expression correctly without including human biases, she said. Chimps often produce what looks like a wide-mouthed toothy “smile” but handlers have learned that this is actually a “fear grin” and means you are more likely to get a bite than a hug.
Animal behaviourists decided to overcome this problem by producing a chimp equivalent of the Facial Action Coding System, developed in 1976 as a way to analyse how the human face moves without reference to the emotion being expressed.
Dr Bard’s group produced a chimp version about five years ago but now she has developed one specifically for infant chimps. “It allows us to separate how the face moves from the emotions involved, how the face acts separately from the emotions.”
The new system is very new but already the team are learning a great deal.
“What we are seeing is a large number of configurations both in human infants and chimpanzee infants,” she said. In fact while human babies display about 13 different expressions that we would loosely describe as a smile, 16 configurations have been defined for baby chimps when smiling.