Like infant humans, newborn monkeys learn by imitation. Researchers at the University of Parma made faces at newborn macaques who then responded in kind. According to the biologists' paper published online along with some amazing video in the freely-accessible Public Library of Science Biology (PLoS) journal, the experiments suggest that this kind of imitation with a purpose, as a form of social learning, is not limited to apes and humans as previously thought. Rather, it evolved more than 25 million years before the monkey ancestors diverged from the human lineage.
From New Scientist (video available there too):
Since newborns cannot see their own faces, they rely on watching adults to learn facial expressions, and mimicry is thought to be crucial to the development of a mother-infant relationship.
Particular brain cells – called “mirror neurons” – fire in a human infant when it watches an adult expression and copies it. Similar mirror neurons "light up" when rhesus monkeys watch another animal perform an action and when they copy that action. This similarity suggests a common brain pathway for imitation in humans and monkeys.
Link to New Scientist, Link to paper in PLoS Biology
