PTI

London, Jan 2: No character sketch of a movie villain is generally complete without a signature evil laugh. But have you ever wondered how laughter evolved? If a study is to be believed, the behaviour started before we split from our close biological cousins -- the apes.

A team of international researchers has carried out the study and found that laughter was not developed first by humans but by the apes as orangutans have a sense of empathy and mimicry which is an essential part of the behaviour, 'The Daily Telegraph' reported on Wednesday.

According to lead researcher Dr Marina Davila Ross of the University of Portsmouth, "What is clear now is the building blocks of positive emotional contagion and empathy that refer to rapid involuntary facial mimicry in humans evolved prior to humankind."

The team came to the conclusion after analysing the way facial expressions were picked up and copied by a group of 25 orangutans at four primate centres around the world. When one of the orangutans displayed an open, gaping mouth - the equivalent of laughter - the researchers examined the response of its playmate.

Dr Ross explained that often the playmate displayed the same expression less than half a second later, suggesting the mimicry was an involuntary display.

According to Dr Ross, the findings shed new light on empathy and its importance for animals which live in groups. "It revealed that empathy of positive emotions or contagious laughter evolved before humans."

The results of the study have been published in the latest edition of the 'Biology Letters' journal.