Individuals may be motivated to limit their use of self-control resources, especially when they have depleted some of that resource. Expecting to need self-control strength in the future should heighten the motivation to conserve strength. In 4 experiments, it was found that depleted participants who anticipated exerting self-control in the future performed more poorly in an intervening test of self-control than participants who were not depleted, and more poorly than those who did not expect to exert self-control in the future. Conversely, those who conserved strength performed better on tasks that they conserved the strength for as compared with those who did not conserve. The underlying economic or conservation of resource model sheds some light on the operation of self-control strength.

Being exposed to the sight and smell of an alcoholic beverage and not drinking it should require self-control. On the basis of the self-control strength model (M. Muraven & R. F. Baumeister, 2000), exerting self-control should lead to poorer performance on subsequent self-control tasks. Using a cue exposure paradigm, the authors had 160 social drinkers alternately sniff water and alcohol. After each trial, the drinkers engaged in 2 self-control tasks: squeezing a handgrip and a self-stopping task. Performance on these tasks was worse after sniffing alcohol than after sniffing water. Mood and arousal did not mediate the effects; urge to drink was negatively related to outcomes. The effects were stronger for individuals high in trait temptation to drink. Resisting the temptation of drinking appears to undermine self-control capacity.

Individuals may desire to diet or restrain from eating certain foods while attempting to quit smoking out of concern for weight gain. However, previous research and clinical tobacco treatment guidelines suggest that concurrent dieting may undermine attempts to quit smoking. The current study applied the self-control strength model, which posits that self-regulation relies on a limited strength that is consumed with use, to test whether resisting tempting sweets would lead to a greater likelihood of subsequent smoking. Participants were 101 cigarette smokers randomly assigned to resist eating either from a tempting plate of sweets or from a plate of less tempting vegetables. All participants were then given a 10-min recess. Whether participants smoked during the break, measured with a breath carbon monoxide sample, served as the primary dependent variable. As predicted, participants who resisted sweets were more likely to smoke during the break (53.2%) than those who resisted vegetables (34.0%), chi2(1, N = 101) = 3.65 p < .05. The findings support the tenets of the self-control strength model and suggest the mechanism by which dietary restraint may harm efforts at quitting smoking.