Testing the role of glucose in self-control: A meta-analysis.

The glucose view of self-control posited glucose as the physiological substrate of self-control "resource", which results in three direct corollaries: 1) engaging in a specific self-control activity would result in reduced glucose level; 2) the remaining glucose level after initial exertion of self-control would be positively correlated with following self-control performance; 3) restoring glucose by ingestion would help to improve the impaired self-control performance. The current research conducted a meta-analysis to test how well each of the three corollaries of the glucose view would be empirically supported. We also tested the restoring effect of glucose rinsing on subsequent self-control performance after initial exertion. The results provided clear and consistent evidence against the glucose view of self-control such that none of the three corollaries was supported. In contrast, the effect of glucose rinsing turned out to be significant, but with alarming signs of publication bias. The implications and future directions are discussed.