In the late 19th century an eccentric agricultural engineer called Max Ringelmann conducted what, to my mind, remains the most important experiment in social psychology. The setup was rather simple. He attached a rope to a dynamometer and asked his students to pull as hard as they could. Tugging alone, the average student pulled a weight of 85kg.
But then the experiment was tweaked: the students were asked to pull together, one behind the other, as a team of seven. The collective weight pulled, on the basis of the earlier experiment, should have been 595kg. In fact it was a mere 450kg. The students were heaving, gasping and looking as if they were trying, but many were going through the motions, letting others take the
