Leader behaviors also appear to play a key role in determining OCBs. As noted earlier, with a few exceptions, almost all of the leader behaviors examined in Table 2 show consistent relationships with employee citizenship behaviors. Unfortunately, the mechanisms through which these leader behaviors influence citizenship behaviors are not always clear. Some of these behaviors, such as supportive leader behavior, may have their primary effect on OCBs through the norm of reciprocity. For example, employees who receive personal support from their leaders may wish to reciprocate by expending extra effort in the form of citizenship behaviors to help the leader. Other behaviors, like providing an appropriate model, may influence OCBs directly through social learning processes, because the leader models various types of citizenship behaviors. Still other leadership behaviors, such as contingent reward behavior, may have a direct impact on citizenship behaviors. For example, if a leader defines performance broadly to include OCBs, and administers rewards contingent upon this definition of performance, then one would expect the frequency of OCBs to increase. Finally, it also is possible that contingent reward behavior and other forms of leader behavior might influence OCBs in other ways. For example, even if managers define performance narrowly to include only in-role behavior, one might expect that a leader’s contingent reward behavior would cause employees to perceive that they are being treated fairly, and/or it might enhance their job satisfaction. Both fairness and job satisfaction have been found to be positively related to OCBs . It has also been argued that the effects of articulating a vision on OCBs are mediated by employees’ trust in their leader, and by job satisfaction. Therefore, future research needs to carefully investigate how and why these leader behaviors influence OCBs.