College students were instructed to press a button for points under a single reinforcement schedule or under a variety of reinforcement schedules. Instructions for a single schedule were either specific or minimal. Instructions on a variety of schedules involved specific instructions on eight different schedules of reinforcement. Subsequent to the varied training, responding under a fixed-interval schedule occurred at a low rate. Both the minimal and specific instruction training led to fixed-interval responding that was similar to the responding exhibited during training. These findings suggest that under certain conditions instructed behavior is sensitive to changes in contingencies.Key words: variety of training, instructed behavior, contingency-shaped behavior, response history, efficiency of responding, reinforcement schedules, button press, adult humans Theoretical and empirical developments in behavior analysis have suggested that behavior acquired by following an instruction may be less sensitive to changes in prevailing contingencies than behavior acquired by shaping (Baron & Galizio, 1983;Baron, Kaufman, & Stauber, 1969;Galizio, 1979;Harzem, Lowe, & Bagshaw, 1978;Matthews, Shimoff, Catania, & Sagvolden, 1977;Skinner, 1966Skinner, ,1969Vaughan, 1985). For example, subjects who have been instructed to respond under one schedule of reinforcement continue to respond as instructed even when the schedule of reinforcement has changed (Baron et al., 1969;Harzem et al., 1978). Insensitivity to changing contingencies is less likely to occur when behavior is shaped by successive approximations, or when instructions are used that do not describe the specific schedules (i.e., minimal instructions; Matthews et al., 1977;Shimoff, Catania, & Matthews, 1981).These findings give rise to the question of which variables determine the sensitivity of human behavior to various and varying contingencies. Weiner (1969Weiner ( , 1970a specific histories of responding under schedules of reinforcement were necessary to bring about sensitivity to fixed-interval (FI) schedules. Training under a differential-reinforcement-of-low-rate (DRL) schedule was sufficient to bring about sensitive performance under FI schedules even when the subjects had a history of responding at high rates under fixed-ratio (FR) schedules. When either no response history or a high-rate response history was provided, high rates occurred under the FI schedule. Weiner's studies, however, did not examine the interaction of reinforcement histories and instructions.Galizio (1979) suggested that under instructed conditions sensitivity occurs only when behavior comes into contact with the change in contingencies. When avoidance behavior was instructed under a point-loss procedure and a schedule was then introduced in which the loss contingency was no longer in effect, behavior did not change. However, when continued responding as instructed resulted in a loss of points, performance quickly adjusted to these conditions. Under the first condition, responses did not...