From the British Psychological Society press release via AlphaGalileo:
“Self-control resembles a muscle. It seems to lose power right after being used and it also gets stronger after exercise.” This is one of the key findings from 20 years of research into willpower, outlined in the February 2012 issue of The Psychologist, which is published today, 26 January 2012.
The overview by Dr Roy F. Baumeister, Professor of Psychology at Florida State University, also highlights research that found self-control tends to break down later in the day, especially if it has been a stressful day. Dr Baumeister said: “Most diets are broken in the evening, sexual misdeeds and addictive relapses occur at the end of long and demanding days.”
Other findings suggest that willpower is an exhaustible resource. Dr Baumeister said: “When you hold your tongue, resist an urge to smoke, drink, or eat, restrain aggression, postpone using the toilet, feign mirth at an inane joke, or push yourself to keep working, it depletes some crucial energy and leaves you with less available for the next challenge.”