In studying the relationship between productivity and efficiency in 1913, French agricultural engineer Maximilien Ringelmann found that members of a group perform worse on average as the size of the group increases. In a tug of war, as the size of a team grows, each member begins to “loaf,” relying on his teammates to put forth the necessary effort. Worse, the team’s growing size makes it increasingly difficult to coordinate its actions.

Interestingly, though, ants have been shown to increase in efficiency when working in teams. New World army ants can carry larger loads as a team than if the burden were distributed among them individually, and Weaver ants organize pulling chains that can effectively double the strength of each member. So “the Ringelmann effect” isn’t inescapable.