Within the field of industrial and organisational psychology, job satisfaction is one of the most extensively researched topics. Several theories of job satisfaction have demonstrated that job control is a predictor of job satisfaction. The most widely citied theory of job control is the job demand-control model (Karasek, 1979). This theory postulates that job control buffers the effects of job demands. This theory is criticised however, for its measurement of job control, and its explanation of the buffering effect. In regards to the former, the job control measure confounds job control with skill variety. Although a revised measure of 'instrumental job control' (Ganster, 1989) has been developed, few researchers have examined this scale. In regards to the latter, the model proposes that job control buffers job demands by allowing the employee to redirect the physiological arousal created from job demands into an appropriate response. This explanation is criticised however as it fails to specify how the arousal produced from job demands is 'redirected', and fails to define what is meant by an 'appropriate response'. Hence, we still do not know how an employee with low job control handles a job demand as compared with an employee with high job control.
In response to this, a more detailed explanation of how instrumental job control buffers job demands is developed. This explanation proposes that instrumental job control buffers job demands by influencing the way employees respond to their demands (i.e., primary control strategies or secondary control strategies; Rothbaum, Weisz & Snyder, 1982). Based on the life span theory of control (Heckhausen & Schulz, 1995), it is expected that employees with high instrumental job control will rarely experience primary control failure, and hence will rely little on secondary control strategies. Employees with low instrumental job control however are expected to experience primary control failure more, and need to implement more secondary control strategies to compensate for this failure.
These propositions concerning instrumental job control, primary control strategies, and secondary control strategies, were developed into a theory of job satisfaction, which also examined the influence of personality and quality of life. The model was tested with a low instrumental job control group (i.e., supermarket register operators) and a high instrumental job control group (i.e., academics). Although the two groups did not report different levels of job satisfaction, the academic group reported higher levels of instrumental job control, higher levels of primary control, and lower levels of secondary control, than the supermarket operators. The predictors of job satisfaction were instrumental job control and primary control for the academics, and quality of life and primary control for the supermarket operators. The implications of these findings, both theoretical and practical, are discussed.