Michael Beecher, a professor of psychology and biology at the University of Washington, developed the hypothesis in the 1980's that social group size predicts individual differences.

Prof Paddy o 'donnell, a social psychologist at Glasgow University, is intrigued by the experiment, having studied earlier research into the effects on individual and group psychology of space travel.

Sociobiology and social psychology have recognized for decades that what is good for the individual is not necessarily what is good for the group, and vice versa.