Persuasive communications, which 140 Ss read aloud, included a statement of the opinion to be learned, followed by neutral material, and then by the argument (information supporting the opinion without repeating i t ) . Delay of argument (time interval between opinion statement and argument) was varied either by interrupting reading of neutral material ( 5 and 2 0 sec.) or without interruption by using neurral material of appropriate length (mean delay = 4 and 20 sec.). Theory (1 ) and research employing the non-interruption method ( 2 ) 5nclicate that the argument functions as a reinforcer of the opinion response, and that delay of argument is analogous to delay of reinforcement, e.g., speed of'agreement (l/latency) is a negatively accelerated decreasing function of delay of argument. In the present study, results with the non-interruption method also show this decremental delay of reinforcement effect on speed (Ms = .057, Mr. = ,029, t = 3.05, df = 30: p < .01, 2-tailed). Speed increased with delay under the interruption method ( i l l s = ,034, Mr. = ,053, r = 2.12, df = 30; p < .05, 2-tailed). Results under the interruption method, while not predictable in derail, can also be interpreted in terms of learning principles. Most Ss have a learning history in which interruption (by parents, teachers, etc.) indicates behavior regarded as incorrect, inadequate, or otherwise disapproved. Social disapproval is a punishment; interruption thus becomes a conditioned punisher. The short delay group is by interruption 5 sec. after stating the opinion, while the long delay group is punished 2 0 sec. after stating the opinion. Thus, delay of reinforcement may be confoundecl with delay of punishment under the interruption method, with the punishment effects predominating in the results.