WASHINGTON - Armies develop teamwork by marching to the same drum beat, just as citizens sing the national anthem before sporting events. A new study suggests that when people engage in synchronised activity, they are more likely to cooperate with other group members.

Stanford University psychologists Scott S. Wiltermuth and Chip Heath conducted a series of experiments to see how synchronous movement affects group interactions.

The results showed that synchrony fosters cooperation - even when all of the volunteers had financial incentives to cooperate, the volunteers from the synchronised groups tended to be more cooperative during the games than volunteers from groups who had moved asynchronously.

Volunteers from the synchronous groups reported greater feelings of being on the same team. Thus, the synchronous participants cooperated during the games in part because they felt as though they were part of a team, said a Stanford release.

Societies rely on cooperation among their members to thrive and be successful.

These findings suggest that cultural practices which involve synchrony (such as dancing, singing or marching) may enable groups to produce members who are cooperative and willing to make personal sacrifices, for the benefit of the group.

These findings were published in the January issue of Psychological Science.