The Effort Economy: Investigating the Relationship between Effort Intensity and Effort Cost

Mental effort is a valuable resource, and spending mental effort is often associated with a costly and aversive experience. Most researchers assume the cost of mental effort is evaluated by comparing some level of mental effort intensity to rest, but the present thesis challenges this idea and instead hypothesizes that effort intensity is compared to some reference point of effort intensity, leaving open the possibility that effort intensity less than a reference point might not carry a cost but be experienced positively. Three experiments built off a paradigm from the mental effort literature and adapted into a decision making framework were conducted to investigate whether mental effort intensity is evaluated relative to a reference point. Experiment 1 employed a close replication of previous research and failed to find evidence for a reference point of effort intensity. Experiments 2 and 3 modified this basic replication to make costs more explicit, and Experiment 3 specifically framed effort in terms of costs and benefits relative to a reference point. Experiment 2 failed to find evidence for a reference point of effort intensity, whereas Experiment 3 found strong evidence in favor of a reference point of effort intensity, but the direction was opposite from that predicted. The strong but reversed finding in Experiment 3 suggests that people can evaluate effort relative to a reference point, but that they might do so opposite from how they evaluate other resources, such as money.