Social loafing

From PsychWiki - A Collaborative Psychology Wiki

In the social psychology of groups, social loafing is the phenomenon that persons make less effort to achieve a goal when they work in a group than when they work alone. This is one of the main reasons that groups sometimes perform less than the combined performance of their members working as individuals.

More basic information can be found on the Wikipedia site - http://en.wikipedia.org/wiki/Social_loafing