San Francisco, April 23 (xinhua) -- by ma Dan Swinging for children is more than just fun. Us researchers have found that preschoolers play on swings together and synchronised movements on the swings can help develop co-ordination.

Researchers at the institute for learning and brain sciences at the university of Washington believe synchronicity improves co-operation, with people turning their attention to others while doing synchronised movements, thus promoting social interaction in a positive way. The study was recently published online in the journal of experimental child psychology.

Researchers created a swing that allows two children to play on at the same time. They divided randomly selected 4-year-olds who didn't know each other into groups that swung simultaneously, those that swung out of sync, and those that didn't. Each group then took part in a series of tasks assessing the level of co-operation, including one in which two children played a computer game in which they could only see the cartoon character appear on the screen if they pressed a button at the same time.

The researchers found that the two children who played on the swings simultaneously completed the task faster, suggesting that they cooperated better than the children who did not move in sync or on the swings. When playing computer games, children who were swinging synchronously were more likely to raise their hands to signal to each other before pressing a button, a strategy that has proved successful.

For 4-year-olds, the researchers explain, synchronizing actions can produce feelings similar to those of the other child, which may encourage the two children to communicate more and try to work together.

Andrew meltzoff, director of the institute for learning and brain sciences at the university of Washington, said collaboration is both social and cognitive because people can work together to solve problems that cannot be solved alone. Before the study began, the researchers did not know that 4-year-olds could improve cooperation through the simple experience of synchronizing actions, so the results are exciting.

The researchers said the findings could have implications for teachers and parents developing children's cooperative abilities by providing them with opportunities to act in sync, such as through music, dance or games.