Knowing isn’t doing. This is an insight pointed out by Yale psychologist Laurie Santos which she calls the “GI Joe Fallacy”. Knowledge doesn’t necessary lead to action or application. One must have an understanding of how to manage their own behavior.

Behavioral interventions are important because they lead to deeper learning and in many causes lead to structural changes in the brain and nervous system which increase the likelihood of performing that behavior in the future.

Social psychologist Roy Baumeister believes self-discipline is the queen of all the virtues (as Martin Seligman puts it).

Psychologist Angela Duckworth assessed 8th grade students’ self-discipline based on answers to a survey and parent/teacher assessments of the students. Note IQ and self-discipline do not correlate with each other significantly. She found self-discipline out predicts IQ for academic success by a factor of about 2 (REFERENCE). They also found the same pattern for obesity: more self-discipline, lesser rates of obesity.

This aligns with past insights from the now famous Standard Marshmallow Study. Children were told they could have one marshmallow now or wait and get a second one or a pretzel stick. The idea was to similuate ability to delay gratification — which is an essential aspect of self-discipline. It was found In follow-up studies that children who were able to wait longer for the preferred rewards tended to have better life outcomes: SAT scores, educational attainment, body mass index, etc.

This would suggest that self-discipline — the ability to control one’s behavior — shapes a variety of life outcomes.

We should note that a replication attempt a larger more diverse sample than the origional study showed only about half the effect of the original study. The predictive power of the marshmallow test has been challenged by several more recent studies. Here is a reference to one from UCLA Anderson Review.

For overviews of Baumeister’s work on self-control, see R. F. Baumeister, M. Gailliot, C. N. DeWall, and M. Oaten, “Self-Regulation and Personality: How Interventions Increase Regulatory Success, and How Depletion Moderates the Effects of Traits on Behavior,” Journal of Personality 74 (2006): 1773–1801; R. F. Baumeister, K. D. Vohs, and D. M. Tice, “The Strength Model of Self-Control,” Current Directions in Psychological Science 16 (2007): 351–55.

Seligman, Martin E. P.. Flourish: A Visionary New Understanding of Happiness and Well-being (p. 374). Atria Books. Kindle Edition.

2A. Ownership (empowerment) and positive emotion support healing.

2B. Willpower is not a scarce resource: ego depletion is inconclusive.

2C. The alternative use test trains creativity.

2D. As humans we have a need to be consistent with how we identify ourselves.

2E. Addiction is any behavior that provides short-term benefit and long-term harm.