Enhanced job control is not the definitive answer to occupational stress. Other factors will impact on the success of control-related interventions; specifically, individual differences that influence the ability to use high control to one’s advantage when working under high demands. Self-determination is one individual difference that might determine whether control is useful for stress reduction. To be self-determined is to act at the highest level of reflection, whereas to be non-self-determined is to let other drives or contingencies be the determinants of your behavior. Self-determined individuals may be more willing or able to use control opportunities available in the environment as an antidote to work stress. In contrast, individuals who are non-self-determined may find high control stress-exacerbating. Thus, the first purpose of this thesis is to establish self-determination as a moderator of the Demand-Control Model (Karasek, 1979) of work strain.
This moderating role for self-determination was tested using a questionnaire study in a sample of administrative employees (Study 1). Results revealed that (1) individuals with high non-self-determination experienced higher anxiety, (2) when individuals high in non-self-determination perceived high job demands, they experienced more health complaints, and (3) when individuals high in self-determination perceived high job control, they experienced greater work engagement. In addition, a 3-way interaction demonstrated that, for individuals low in non-self-determination, high job control had the anticipated stress-buffering effect on engagement. In addition, low job control was stress-exacerbating. Contrary to expectations, for those high in non-self-determination, high job control was just as useful as low job control as a stress-buffer. For these non-self-determined individuals, passive jobs (i.e., jobs with low demands and low control) resulted in the least work engagement.
The second purpose of this thesis is to examine the causal implications of the interactive effects of self-determination, demand, and control (Studies 2 – 4). As such, an experimental methodology utilizing a work simulation (i.e., an inbox activity) was adopted. In Study 2, the impact of global self-determination, demand, and control was examined for a range of task outcomes (i.e., including anxiety, situational motivation, and task performance). Results revealed that non-self-determined individuals experienced high-strain task conditions (i.e., high demand and low control) as enjoyable as their intrinsic motivation was maintained from baseline. In contrast, typically active task conditions (i.e., high demand and high control) significantly decreased these participants’ intrinsic motivation from baseline. Similar to the pattern of findings on work engagement in Study 1, passive task conditions (i.e., low demand and low control) resulted in the least task performance for non-self-determined individuals. No interactive effects with the self-determined form of motivation emerged.
For Studies 3 and 4, a within-participants design was adopted. Drawing on a process approach (Larsen, 1989), it was anticipated that a within-participants design would reveal a more accurate understanding of the role of individual differences in self-determination on the dynamic effects of situational outcomes that reflect stress and coping processes. In Study 3, reactions to fluctuations in workload, at different levels of work control, was examined across a range of outcomes including anxiety, coping strategies, task motivation, and task performance. Results revealed that non-self-determined individuals experienced more anxiety. In addition, for these individuals, working under high control increased anxiety at trial 3 (i.e., whether workload increased or decreased, the change in workload was stressful). Moreover, under high control, intrinsic motivation towards the task declined after trial 1. Despite the control available, these individuals increased active coping efforts in response to increased workload at trials 3 and 4. These individuals also performed better the second time they experienced high workload. For individuals with high self-determination, anxiety did not change across conditions or trials. For these individuals, planning coping decreased over trials as workload increased, and when control was high, planning coping increased over trials as workload decreased. While non-self-determined individuals found high control stressful, self-determined individuals used high control to implement an adaptive emotion-regulation strategy (i.e., planning coping) to meet the demands of the situation.
In Study 4, participants’ reactions to changes in work control were examined on the outcomes of anxiety, cognitive reappraisal, task motivation, and task performance. Results revealed that (1) non-self-determined individuals experienced higher anxiety, and (2) self-determined individuals experienced increased intrinsic motivation over trials. In addition, individuals with high self-determined motivation experienced increased positive reappraisal when control was high at both trials or when control was increased in the second trial. Participants with high non-self-determined motivation who experienced high work control across both trials reported an increase in anxiety over trials and increased fatigue overall. The use of an adaptive emotion-regulation strategy (i.e., positive reappraisal) might explain why self-determined individuals experienced less stress reactivity (i.e., anxiety and fatigue) compared to non-self-determined individuals.
Overall, the findings demonstrate that (1) individuals’ high in non-self-determined motivation find high control stress-exacerbating rather than stress-buffering, and (2) individuals’ high in self-determined motivation use more adaptive emotion-regulation strategies (i.e., planning coping and positive reappraisal) when they have access to high work control. Overall, this program of research demonstrates that control is not always beneficial to stress-reduction when working under high demands.