Monkeys copy movements of their peers just like humans: Study

London: Monkeys can synchronise their movements with each other just like humans do when they hit the dancefloor, a new study has found.

Scientists have shown for the first time that primates adapt their movements to be in tune with their peers, just like people do. Humans unconsciously modify their movements to be in unison with others. For example, people adapt their pace to walk in step or clap in unison at the end of a concert. The phenomenon is thought to reflect bonding and enable human interaction, the `Daily Mail` reported. Researchers at the RIKEN Brain Science Institute in Japan have now shown that pairs of macaque monkeys will also spontaneously coordinate their movements. The scientists said the research opens the door to much-needed studies which could shed light into human behavioural dysfunctions such as autism spectrum disorders - where patients have difficulty relating to others - and echopraxia and echolalia - where they uncontrollably imitate others. The research team, led by Doctor Naotaka Fujii, developed an experimental set-up to test whether pairs of Japanese macaque monkeys would synchronise a simple push-button movement. Before the experiment, the monkeys were trained to push a button with one hand. In a first experiment, the monkeys were paired and placed facing each other and the timing of their push-button movements was recorded. The same experiment was repeated, but this time each monkey was shown videos of another monkey pushing a button at varying speeds. And in a last experiment the macaques were not allowed to either see or hear their video-partner. The results show that the monkeys modified their movements - increased or decreased the speed of their push-button movement - to be in synchrony with their partner, both when the partner was real and on video. The speed of the button pressing movement changed to be in harmonic or sub-harmonic synchrony with the partners` speed. However, different pairs of monkeys synchronised differently and reached different speeds, and the monkeys synchronised their movements the most when they could both see and hear their partner. The researchers said that this behaviour cannot have been learnt by the monkeys during the experiment, as previous research has shown that it is extremely difficult for monkeys to learn intentional synchronisation. The reasons why the monkeys showed behavioural synchronisation are not clear. It may be a vital aspect of other socially adaptive behaviour, important for survival in the wild," Fujii said. The study was published in the journal Scientific Reports. PTI