THE FOUR EFFECTS OF COOPERATION.

The article presents information on the four effects of co-operation. In spite of the rapid development of social psychology in recent years, relatively little attention has been paid to the problems of cooperation. There is some experimental evidence, which, however, has remained rather unsystematized. The work songs, well known also from studies of primitive societies, obviously served the purpose of temporal coordination. There is no doubt that the average effect of cooperation is a very important one, and very well distinguished from the other ones. It occurs in a lot of situations in daily life say, when school marks, obtained from different teachers, are combined. The rapid development of science during the last 100 years is certainly a consequence not only of the accumulated knowledge, forming a better base for further work, but also of the rapid increase of the number of scientists. This number is of importance in two ways. It means a broadening of the field under research more problems can be attacked. But it also means an increasing probability of certain valuable scientific performances, i.e., when different workers attack the same problem or group of problems.