Humans were presented with a task that required moving a light through a matrix. Button presses could produce light movements according to a multiple fixed-ratio 18/differential-reinforcement-oflow-rate 6-s schedule, with components alternating every 2 min. Moving the light through the maze earned points worth chances on money prizes. In Experiment 1 four conditions were assessed through between-subject comparisons: minimal instructions, instructions to press rapidly, instructions to press slowly, and instructions that sometimes rapid responding would work while at other times a slow rate would work best. Subjects responded in three successive sessions of 32 min each. The results suggested that instructions affected the nature of the contact made with the programmed consequences and thus subsequent performance. In some cases, responding seemed to result from added contingencies introduced by stating rules. In Experiment 2 the relative contribution of these two effects was assessed by presenting and then withdrawing two lights that had been paired with two specific instructions: "Go Fast" or "Go Slow." There were three conditions. In one condition, only the Go Fast light was on; in a second, only the Go Slow light was on; and in a third, the lights alternated each minute. In each condition, half the subjects had all instruction lights turned off after the first session. The results once again showed an effect of instructions on contact with the programmed consequences. However, responding sometimes continued in a manner consistent with added contingencies for rule-following even when the programmed consequences had been contacted and would have controlled a different type of responding in the absence of instructions. The relevance of added contingencies for rule-following in determining the effects of explicitly programmed consequences is emphasized.

Acceptance approaches , which have been receiving increased attention within behavior therapy, seek to undermine the linkage between private events and overt behavior, rather than attempting to control the form or frequency of private events per se. Research comparing control versus acceptance strategies is limited. The present study examined the behavioral and subjective impact of a control-based versus acceptance rationale, using a cold pressor task. Subjects in the acceptance group demonstrated greater tolerance of pain compared to the controlbased and placebo groups. Only the control-based rationale targeted the subjective experience of pain but it did not differ across rationales. Results confirmed that acceptance was effective in manipulating the believability of reason giving, a key process measure. By encouraging individuals to distance themselves from their private events, acceptance methods may help reduce the use of emotional reasons to explain behavior and hence shift concern from moderating thoughts and fee lings to experiencing the consequences of one's action. Acceptance is a promising new technique. Its effect is all the more surprising given that it teaches principles (e.g., "thoughts do not cause behavior") that run counter both to the popular culture and to the dominant approaches within empirical clinical intervention.Requests for reprints should be sent to

Two studies were conducted to identify mechanisms responsible for observed "self-reinforcement" effects. In Experiment 1, using a studying task, self-reinforcement procedures did not work when they were private (i.e., when others are not aware of the goals or contingencies), but did work when they were public. Self-delivery of consequences added nothing to the effectiveness of the procedure. The data suggested that public goal setting was the critical element in the procedure's effectiveness. In Experiment 2, an applied extension, goal setting alone was effective in modifying over a long time period studying behaviors of people with significant studying difficulties, but only when the goals were known to others. Overall, the two experiments make more plausible the view that self-reinforcement procedures work by setting a socially available standard against which performance can be evaluated. The procedure itself functions as a discriminative stimulus for stringent or lenient social contingencies. The application of this mechanism to other problems of applied significance is briefly discussed.