Abstract
In search of an explanation of rather frequent discrepancy between leader's role behavior and members' perception of his leadership function and their relations to the group productivity 30 fiveperson groups of junior high school pupils were asked to perform a simple repetitive task under the supervision of a classmate leader who had been selected on the basis of his predisposition [(P) or (M)] assessed by a guess-who test and whose role behavior [type P, M, or O] had been prescribed by the experimenter and trained in advance. Members' perception of leadership functions, motivation to work, attraction to the group and group productivity under the six experimental conditions [(P) P, (P) M, (P) O, (M) F, (M) M, and (M) O] were compared. Major findings are: (1) predisposition (M) is easily perceived as constituent of M-function, whereas (P) can hardly be perceived as P-function without an aid of role behavior P; (2) there are two kinds of forces affecting group productivity, which are operative through some pre or semi-conscious processes, one originating from leader's role behavior and the other from his predisposition.
