The role of excess cognitive capacity in the relationship between job characteristics and cognitive task engagement

A model is presented in which two categories of individual differences, differences related to task capacity and differences related to task motivation, are proposed to influence the relationship between task characteristics and cognitive task engagement. It is proposed that task characteristics will interact with the performer's task capacity to influence the excess cognitive capacity available to the task performer. To the degree one's capabilities meet or exceed the demands of the job, excess cognitive capacity is more likely. The relationship between excess cognitive capacity and cognitive task engagement is then moderated by factors influencing one's task motivation, and by cognitive and physical interventions if the excess capacity is actively utilized in a safe manner. If the excess cognitive capacity is safely utilized, or if task motivation is high, cognitive task engagement is more likely. Implications of the model for human resource management are discussed.