"In 1958... psychologists let groups of four people brainstorm about the practical benefits or difficulties that would arise if everyone had an extra thumb on e

"In 1958... psychologists let groups of four people brainstorm about the practical benefits or difficulties that would arise if everyone had an extra thumb on each hand after next year." Wait.. What? The power of brainstorming is apparent when two people are thinking about something they will both use. If it's directly useful to both of them then two heads are about four times better than one, if not closer to ten times better.