The dilution model: how additional goals undermine the perceived instrumentality of a shared path.

Six experiments tested a dilution model of self-regulation, whereby increasing the number of goals (e.g., building muscles and losing weight) that a single means (e.g., exercising) can satisfy reduces the perception of its instrumentality with respect to each goal. The authors found that an increase in the number of simultaneous, salient goals that can be satisfied via a single means weakens the associative strength between that means and each individual goal, and as a result, individuals perceive the means as less effective for the attainment of each goal. Consequently, means that are connected to multiple (vs. single) goals are less likely to be chosen and pursued when only one of these goals is activated.