The adaptiveness of self-control: simulation of foraging mice

Tobin and Logue (1994) have proposed that interspecific differences in rates of delay discounting are driven by differences in metabolic rates. This "metabolic hypothesis" argues that under conditions of deprivation impulsive animals will out-compete self-controlled animals. The authors report here a series of modeling experiments testing the predictions of Tobin and Logue (1994) using a simulated population of "mice" in which the average meal size, the standard deviation of the meal size, collection risk and maximum delay were parametrically manipulated. The authors found that for all meal size averages and standard deviations self-controlled "mice" out-competed impulsive "mice" and that this advantage was most marked under conditions of deprivation. Conversely, increasing collection risk or maximum delay promoted the dominance of impulsive strategies. These results call into question the "metabolic hypothesis" and suggest that interspecific differences in collection risk may drive differences in rates of delay discounting.