So, Last time I wrote about building your willpower muscles so they will last longer. But, how does your willpower get tired in the first place. The psychologists in charge of such things call the loss of willpower ego-depletion and making harder decision is what causes it.
In the first experiment, a bowl of radishes and a stack of freshly-baked chocolate chip cookies were placed on a table. Subjects in the experiment were instructed to skip a meal in order to induce hunger. Three conditions were established: radish-eating, chocolate-eating, and non-eating. The non-eating condition constituted the control. In the radish condition, subjects were left alone in the room and asked to eat two or three radishes, while avoiding the chocolate. In the chocolate condition, subjects were asked to eat two or three cookies, while avoiding the radishes. The non-eating subjects did not participate in the eating part of the experiment. Following the eating exercise, subjects were instructed to attempt to solve a geometrical drawing puzzle, which unbeknownst to them, was actually impossible to solve. Subjects were also informed that if they wished to quit trying to solve the puzzle, they would be able to do so. Results showed that participants in the radish condition quit sooner on the puzzle task than did participants in either the chocolate condition or the non-eating condition. Also evident was that the chocolate condition did not differ from the no-food control condition in persistence in trying to solve the puzzle. Participants in the radish condition also reported being more tired after the puzzle task than those in the chocolate or non-eating conditions. These findings showed support for the theory of ego depletion. In the radish condition, the subjects’ resistance to the temptation to eat chocolate resulted in the decrease of some psychic energy. The depleted level of this energy resulted in radish-condition subjects to give up more easily on the puzzle task. Conversely, subjects in the chocolate and non-eating conditions did not have their resource taxed, and therefore showed no decrease in persistence in the puzzle task.
The second experiment aimed to study whether ego depletion could impair performance on solvable, rather than unsolvable, tasks. The first part of the study involved having participants watch movies. In the suppress-emotion condition, subjects were asked to try to not show or feel emotions while viewing the movies. On the other hand, participants in the no-regulation condition were instructed to let out their emotions while watching the movies. Half of the subjects in each condition were then shown a positive, humorous clip of video, while the other half were presented with a negative, sad clip of video. Following the viewing, participants were given anagram letter sets that they were asked to solve. The results showed that subjects in the suppress-emotion condition solved significantly fewer anagrams than those in the no-regulation condition. The type of movie that was watched had no affect on the ability to solve anagrams. In this case, self-regulation in the form of emotion suppression was followed by poorer performance in solving anagram puzzles. This provided further evidence that some resource was depleted after an act of volition. Other experiments performed by Baumeister and his colleagues showed that making a responsible decision impaired subsequent self-control and that an initial act of self-control led to increased passivity. The latter can be explained by the fact that activity requires cognitive energy that is presumably depleted after an act of self-control.”