http://repub.eur.nl/res/aut/14498/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/20180/ 2010-06-01T00:00:00Z In social identity analyses of leadership the role of leader group prototypicality (the extent to which the leader is representative of the collective identity) in leadership effectiveness is emphasized. We extend this analysis by identifying role ambiguity as a situational influence that feeds into the desire to reduce uncertainty, as a moderator of the relationship between leader group prototypicality and indicators of leadership effectiveness (perceived effectiveness, job satisfaction and turnover intentions). Role ambiguity is proposed to lead people to turn to their group memberships, making leadership effectiveness more contingent on the extent to which leaders are group prototypical. Results of a survey of n=368 employees of four Italian companies supported this hypothesis. Role ambiguity and leader group prototypicality interacted in predicting perceived effectiveness, job satisfaction and turnover intentions, such that leader group prototypicality was more strongly related to leadership effectiveness for employees experiencing greater role ambiguity. http://repub.eur.nl/res/pub/11816/ 2007-01-01T00:00:00Z The social identity model of organizational leadership (SIMOL; Hogg and van Knippenberg, 2003 was extended analyzing the degree of employees’ effort as individual outcome of leadership effectiveness. Two studies were conducted with Italian participants. Study 1 was a survey conducted with 68 employees of a medium size company. Results showed the significant two-way interaction effect of team identification × leader group prototypicality in predicting employees’ work effort. Study 2, including 124 students, was a 2 × 2 within subject design (team identification high vs. low × leader group prototypicality high vs. low) using scenarios. Results confirmed experimentally the causal relationship between such variables: subjects in condition of high team identification and high leader group prototypicality perceive leaders as more effective than the subjects in the other three conditions. http://repub.eur.nl/res/pub/11863/ 2005-08-01T00:00:00Z The moderator effect of need for closure on the relations between leader group prototypicality and different aspects of leadership effectiveness (perceived effectiveness, job satisfaction, self-rated performance, and turnover intentions) was examined. Need for closure, reflecting a desire to reduce uncertainty, was proposed to lead people to turn to their group memberships, thus making leadership effectiveness more contingent on the extent to which leaders are group prototypical. This hypothesis was tested in a survey of N =242 employees of 3 Italian companies. Results indicated the expected 2-way interaction between need for closure and leader group prototypicality in predicting leadership effectiveness: the relationship between leader group prototypicality and leadership effectiveness is stronger for high need for closure than for low need for closure employees. The way in which these findings extend the social identity theory of leadership, as well as more applied implications is discussed.