Reformative self-control and discounting of reward value by delay or effort

Abstract

The relation between reformative self-control and discounting of reward value by delay or effort was examined. Thirty-two Japanese undergraduates were selected based on their scores on a standardized pencil and paper test of self-control, the Redressive-Reformative Self-Control Scale (Sugiwaka, 1995). The subjects indicated their preference (i) between a hypothetical 100 000 yen reward available with various delays and a certain reward of variable amount available immediately; or (ii) between a hypothetical 100 000 yen reward available with various efforts and a certain reward of variable amount available without effort. The discounting of delayed reward value was described well by a hyperbolic function proposed by Mazur (1987). The slopes of the delayed discounting curves were steeper for subjects who scored low on the Reformative Self-Control Scale, which is a measure of reformative self-control and a subscale of the Redressive-Reformative Self-Control Scale. The discounting by effort was also described well by the hyperbolic function. The slopes of the effortful discounting curves did not correlate to those of the delayed discounting curves. The slopes were not systematically different across the groups of subjects with different scores on the reformative self-control scale.