Turn It All You Want: Still No Effect of Sugar Consumption on Ego Depletion

Florian Lange ,Caroline Seer ,Mariça Rapior ,Jan Rose ,Frank Eggert

doi:10.5334/jeps.cc

Florian Lange , Caroline Seer + Show 3 more

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https://doi.org/10.5334/jeps.cc

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Abstract

After having completed an initial self-control task, individuals typically show less self-controlled behavior on a consecutive task. In addition, this so-called ego-depletion effect is assumed to be alleviated by the consumption of sugar-containing drinks. However, a recent replication study indicates that this effect has been substantially overestimated. In contrast to mainstream ego-depletion research, initial and consecutive self-control tasks were identical in that study. Here we evaluate the generalizability of these results by testing 70 participants on a dual-task paradigm involving dissimilar tasks. Between self-control tasks, participants consumed a drink containing either sugar or an artificial sweetener. Results suggest that sugar consumption does not counteract ego depletion even when dissimilar self-control tasks are used.

Highlights

From a physiological point of view, it has been demonstrated that human brain functioning is unlikely to be impaired by the negligible amount of glucose consumed during self-control tasks (Kurzban, 2010; see Beedie & Lane, 2012)
It remains possible that the experiment reported in Lange and Eggert (2014) failed to induce ego depletion and that the exhaustion of self-control resources can be moderated by sugar consumption only when dissimilar tasks are used
If the two groups did not differ in performance on the second self-control task, ego depletion could be concluded to be unaffected by sugar intake, even when self-control is required in different contexts before and after the experimental manipulation

Summary

Introduction

From a physiological point of view, it has been demonstrated that human brain functioning is unlikely to be impaired by the negligible amount of glucose consumed during self-control tasks (Kurzban, 2010; see Beedie & Lane, 2012). When using more powerful designs than applied in the original studies, neither the correlation between blood glucose levels and task performance on a second self-control task in ego-depleted individuals (Dvorak & Simons, 2009; reanalyzed by Schimmack, 2012) nor the counteracting effect of glucose administration (Lange & Eggert, 2014) could be replicated In view of these reasonable challenges of the glucose model of self-control, further replication studies are crucial to determine the reliability of the original findings (Frank & Saxe, 2012; Schimmack, 2012; Simmons, Nelson, & Simonsohn, 2011). If the two groups did not differ in performance on the second self-control task, ego depletion (or ego-depletion-like effects) could be concluded to be unaffected by sugar intake, even when self-control is required in different contexts before and after the experimental manipulation

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