The Muscle Analogy of Self-Control
In my book Willpower Condensed, I wrote that we can strengthen our will like a muscle:
Track the food you eat or improve your posture for two weeks and you’ll be more tenacious at holding a handgrip. Stick to an exercise plan or keep track of your spending for two months and you’ll have more willpower to resist distraction. Use your non-dominant hand for everyday activities or monitor your language for two weeks and you’ll increase your puzzle-solving persistence. Squeeze a handgrip twice a day for as long as possible and two weeks later you’ll have better cycling endurance.
A plethora of psychological studies showed that baseline self-control can increase over weeks of regular self-control training—just like a skeletal muscle. Exert willpower today and you will be stronger tomorrow!
Now, however, the muscle analogy of self-control seems to meet the same devastating fate as the ego depletion theory.
A recent study (Lee & Kemmelmeier, 2017) reexamined the effects of willpower training:
- Training group subjects had to use their non-dominant hand for mundane, daily tasks (carrying objects, brushing teeth, stirring beverages, etc.).
- Control group subjects had to keep a “temptation journal” so that they would still think about self-control but not necessarily exercise it.
Every three days, participants were reminded to follow the instructions and asked to report their compliance. Before training and two weeks into it, their self-control was assessed with three measures:
- subjective measure: self-reported self-control (two questionnaires);
- cognitive measure: inhibitory executive control (Stroop test performance);
- physical measure: squeezing a handgrip exerciser for as long as possible.
The results: disappointing null findings. None of the three measures improved with self-control training.
Although we cannot conclude too much from just a single failure of replication, we must take into account that the experimental design and statistical methods used in this study were great improvements over previous ones and, importantly, not subject to the problematic ego depletion paradigm.
Practically, I do not want to take away anything from this study except an enhanced sense of scientific curiosity. Human cognition/volition is flabbergastingly complex—this is what the science shows. Everything else, practical implications in particular, should be left to critically reflected personal experiences and the self-help principles we derive from them.
The belief that we cannot exercise our will is simply not an option if we want to live a good life. The truth is: We can pursue pride, we can pursue strength, and we can pursue a greater power of will. It is this pursuit that grows our discipline, grows our freedom within. And we know from science that we can train our brain, mind, body, and heart to foster that growth.
In the brain, the principle is frontal lobe plasticity; in the mind, the principle is pride anticipation; in the body, the principle is parasympathetic activation; and in the heart, the principle is vagal tone modulation.
Lee BM, Kemmelmeier M (2017). How reliable are the effects of self-control training?: A re-examination using self-report and physical measures. PLoS One 12(6), e0178814, doi: 10.1371/journal.pone.0178814.