Most of us will be familiar with these events; temporarily disregarding a diet, gratuitously lashing out at a co-worker after a stressful workday, having difficulty concentrating on a cognitive task after driving for a long period. Although most of us realize some tasks tend to tire us and affect our capacity to manage our emotions and concentration, the far-ranging pattern at play in these contexts can still be difficult to model into a cohesive worldview. Empirical research has provided us with a general term for these dynamics; Ego Depletion.

The best way to approach Ego Depletion may be to perceive the brain – and active self – as a muscle, which can be strained by a multitude of efforts common in everyday life. Despite the seemingly petty nature of decisions like which consumer product to purchase, or which food product to eat, the cumulative impact of these numerous decisions on our brain’s resources can become significant.

Baumeister, Bratslavsky et al. produced a seminal paper establishing the concept of Ego Depletion1 in 1998, in which a series of four experiments were done to evaluate the effect of mental strain on participants. The findings showed that being subjected to these challenges reduced performance in subsequent tests. These experimental findings were replicated in multiple studies 234, and in different settings.

The state of ego depletion has been shown to have an effect on a surprisingly wide range of behavior5. A well-known example comes from Danziger et al. (2011)6, in which researchers observed parole judges’ leniency towards claimants varied substantially throughout the day, with lower leniency the farther the judges were from having had a lunch break.

The reaction to these findings must obviously be tailored to the professional (and personal) fields they affect. Therefore, the policy implications of these findings would be impossible to summarize here. Individuals, however, can perhaps use the knowledge of these dynamics to better understand that other individuals’ behavior is often affected by these dynamics, altering their behavior in ways they had not necessarily planned.

Although recent research7 has challenged the size of the effect of ego depletion on behavior, as well as certain methods used to recover from it (e.g., glucose intake), the literature and the experimental settings remain diverse and robust enough to consider the existence of ego depletion, as a representation of mental fatigue, a stylized fact.

 

Significant papers

[1] Baumeister, R. F., E. Bratslavsky, M. Muraven, and D. M. Tice. “Ego Depletion: Is the Active Self a Limited Resource?” Journal of Personality and Social Psychology 74, no. 5 (1998): 1252-65.

[2] Schmeichel, B. J., K. D. Vohs, et al. (2003). “Intellectual Performance and Ego Depletion: Role of the Self in Logical Reasoning and Other Information Processing.” Journal of Personality and Social Psychology 85(1): 33-46.

[3] Gino, F., M. E. Schweitzer, et al. (2011). “Unable to resist temptation: How self-control depletion promotes unethical behavior.” Organizational Behavior and Human Decision Processes 115(2): 191-203.

[4] Hagger, M. S., C. Wood, et al. (2010). “Ego Depletion and the Strength Model of Self-Control: A Meta-Analysis.” Psychological Bulletin 136(4): 495-525.

[5] Baumeister, R. F., K. D. Vohs, et al. (2007). “The strength model of self-control.” Current Directions in Psychological Science 16(6): 351-355.

[6] Danziger, S., J. Levav, and L. Avnaim-Pesso. “Extraneous Factors in Judicial Decisions.” Proceedings of the National Academy of Sciences of the United States of America 108, no. 17 (2011): 6889-92.

[7] Hagger, M. S. and N. L. D. Chatzisarantis (2016). “A Multilab Preregistered Replication of the Ego-Depletion Effect.” Perspectives on Psychological Science 11(4): 546-573.

 

Additional references

Baumeister, R. F., E. A. Sparks, et al. (2008). “Free will in consumer behavior: Self-control, ego depletion, and choice.” Journal of Consumer Psychology 18(1): 4-13.

DeWall, C. N., R. F. Baumeister, et al. (2007). “Violence restrained: Effects of self-regulation and its depletion on aggression.” Journal of Experimental Social Psychology 43(1): 62-76.

Hagger, M. S., C. Wood, et al. (2009). “The strength model of self-regulation failure and health-related behaviour.” Health Psychology Review 3(2): 208-238.

Hofmann, W., K. D. Vohs, et al. (2012). “What People Desire, Feel Conflicted About, and Try to Resist in Everyday Life.” Psychological Science 23(6): 582-588.

Inzlicht, M. and B. J. Schmeichel (2012). “What Is Ego Depletion? Toward a Mechanistic Revision of the Resource Model of Self-Control.” Perspectives on Psychological Science 7(5): 450-463.

Kouchaki, M. and I. H. Smith (2014). “The Morning Morality Effect: The Influence of Time of Day on Unethical Behavior.” Psychological Science 25(1): 95-102.

Moller, A. C., E. L. Deci, et al. (2006). “Choice and ego-depletion: The moderating role of autonomy.” Personality and Social Psychology Bulletin 32(8): 1024-1036.

Webb, T. L. and P. Sheeran (2003). “Can implementation intentions help to overcome ego-depletion?” Journal of Experimental Social Psychology 39(3): 279-286.

Schmeichel, B. J. and K. D. Vohs (2009). “Self-Affirmation and Self-Control: Affirming Core Values Counteracts Ego Depletion.” Journal of Personality and Social Psychology 96(4): 770-782.

Stucke, T. S. and R. F. Baumeister (2006). “Ego depletion and aggressive behavior: Is the inhibition of aggression a limited resource?” European Journal of Social Psychology 36(1): 1-13.

Vohs, K. D., B. D. Glass, et al. (2011). “Ego depletion is not just fatigue: Evidence from a total sleep deprivation experiment.” Social Psychological and Personality Science 2(2): 166-173.

 

Counter-argument

Inzlicht, M., B. J. Schmeichel, et al. (2014). “Why self-control seems (but may not be) limited.” Trends in Cognitive Sciences 18(3): 127-133.