Evoking the ego-depletion effect using incentives and task duration in a sequential-task experiment

Although there has been substantial support for the strength model of self-control (Baumeister’s, 1998) in the last two decades, questions have been raised regarding its validity as a recent meta-analysis by Carter and McCullough (2014) concluded the ego-depletion effect was statistically negligible. We postulate that these results may be due to the previous studies not ascertaining how much exertion was put into the first task of a sequential-task experiment, resulting in conflicting outcomes of the depletion effect. The primary goal of this study was to explore possible methods to reliably evoke the ego-depletion effect during a strength model experiment. This project involves two laboratory experiments using the sequential-task experimental paradigm while attempting to manipulate the self-control effort exerted during the first task by either offering monetary incentives or extending task durations in order to manipulate self-control exertion level. Results found that neither offering of incentives nor extending of task duration was able to effectively trigger the ego-depletion effect. These results illuminated critical methodological shortcomings in the ways that strength model have been tested in the past and suggests the research focus in the immediate future is to re-examine some experiment protocols of strength model research.