Research has established that acts of self-control deplete a resource required for subsequent self-control tasks. The present investigation revealed that a psychological intervention—self-affirmation—facilitates self-control when the resource has been depleted. Experiments 1 and 2 found beneficial effects of self-affirmation on self-control in a depleted state. Experiments 3 and 4 suggested that self-affirmation improves self-control by promoting higher levels (vs. lower levels) of mental construal. Self-affirmation therefore holds promise as a mental strategy that reduces the likelihood of self-control failure.
Source: “Self-affirmation and self-control: Affirming core values counteracts ego depletion.” from Journal of Personality and Social Psychology