Main and interactive effects of weekly transformational and laissez‐faire leadership on followers’ trust in the leader and leader effectiveness

Leaders' behaviour fluctuates over time, and leaders use different behaviours that impact their

followers. Whereas transformational leadership is associated with positive outcomes, laissez-faire

leadership negatively affects followers. An important question that remains unanswered is how

the joint use of both leadership behaviours relates to leader effectiveness. In this study, we

answer this question by investigating the main and interactive effects of transformational and

laissez-faire leadership behaviours on perceived leader effectiveness. Specifically, we

hypothesized that leaders are perceived as less effective by their followers when they use both

transformational and laissez-faire leadershiip because it reduces followers' trust in their leader. Data came from 59 employees who participated in a weekly diary study and provided 228 data

points. Results showed that both weekly transformational and laissez-faire leadership predicted

trust in the leader assessed in the following week. Trust in the leader, in turn, positively predicted

perceived leader effectiveness assessed one week later. Contrary to our predictions, we found that

trust in the leader and perceived leader effectiveness were reduced when leaders showed a

combination of less (-1SD) weekly transformational and more (+1SD) laissez-faire leadership

than usual. In the weeks that leaders showed more (+1SD) transformational leadership, followers

had more trust in their leader and perceived their leader to be more effective regardless of the leader's use of laissez-faire. These findings suggest that it is important to take interactions

between different leadership behaviours into account when studying leadership effectiveness.