Basically, this is a form of Social Loafing, where the more people involved in a task, the less effort each of these people will put in. If the Ringlemann Effect can be overcome, team performance as a whole can be improved.
The original research measured the amount of force produced by an individual in a tug of war. The subject pulled on one end of a rope, while the amount of force was measured on a strain gauge. Subjects were added to the rope one at a time, and although the force increased (due to more people pulling on the rope), the amount of force that each person was creating was less).
Rather than three people creating a force equal to the summation of their individual pulls, they were only able to create two and a half times the expected force. By the time eight people were on the rope, they were generating less than HALF of the expected force.
The theory is that the more people there are, the less likely your performance will be evaluated. It seems that it is the evaluation of performance that is the biggest influencing factor.
To lessen the Ringlemann Effect, make sure that members of a team are individually analysed (or at least give the impression of analysis) so sub-par performance becomes apparent.
