The power of teamwork might be nothing but a big myth. While many hands might make light work, it doesn't mean that everyone is pulling in their weigh equally. 

This term is known as "Social laziness," in which the more people are working a task, the less they're likely to work. The issue has to do with the logistical problems of resources and communication in large groups. All it takes is one fight, or one person to slow a group down dramatically.

The most basic way to demonstrate this would be the "Ringelmann Effect" which stems from a simple experiment. done by Max Ringelmann, a professor of agricultural engineering.

The experiment involved getting people to pull on a rope attached to a force meter. First they pulled singly, and then together. Three people provided 2 and a half times the power of one person pulling. Eight people got about four times the power.

The results showed that the more people called in to pull, the less each individual tried. This is the first attempt to quantify why multiplying the number of people taking on a task never seemed to make the task five times more achievable.

[Psyblog, Point of Focus.]