The goal of this study is to examine the moderating effect of two group characteristics, group size and group cohesiveness, on the relationship between organizational commitment and transformational leadership, on the one hand, and in‐role and extra role behaviors, on the other. Based on social exchange theory, the main expectation was that the two group characteristics would create different conditions for exchange, influencing the relationship between determinants and outcomes.
The sample was 223 Israeli employees from a variety of occupations (nurses, social workers, physiotherapists, laboratory employees, administrative staff, etc.) working in 31 medical units in two health care organizations (a response rate of 59 percent).
HLM analyses showed strong moderating effects of both group cohesiveness and group size. The findings show that group characteristics strongly affect the nature and direction of the relationship between the examined determinants and the behavioral outcomes. The findings also revealed a significant three‐way interaction, demonstrating that group size and cohesiveness have an important joint effect. Cohesiveness differed in its effects on how commitment and transformational leadership are related to organizational citizenship behavior (OCB) and in‐role performance depending on whether the groups were large or small.
This study examines group size as a possible moderator, a construct only rarely considered in studies that attempt to predict OCB. The inclusion of leadership style is an important addition, considering that a good part of the exchange processes that take place in this context are between the employee and his/her supervisor.
