Perhaps the first social psychology laboratory experiment was undertaken in this area by Norman Triplett in 1898.
In his research on the speed records of cyclists, he noticed that racing against each other rather than against the clock alone increased the cyclists' speeds. He attempted to duplicate this under laboratory conditions using children and fishing reels. There were two conditions: the child alone and children in pairs but working alone. Their task was to wind in a given amount of fishing line and Triplett reports that many children worked faster in the presence of a partner doing the same task.
Triplett's experiments demonstrate theco-action effect, a phenomenon whereby increased task performance comes about by the mere presence of others doing the same task.