The present experiment studied the relationship between interresponse intervals and behavioral variability. Subjects emitted sequences of 4 keypresses on two keys on a variability schedule that delivered points when the current 4-response sequence differed from the previous 5 sequences. Three experimental conditions were studied; no interresponse interval, 4-s interresponse interval and 8-s interresponse interval. Interresponse intervals followed each of the first three responses in each sequence. Two groups were used to study initial training histories. Group 1 was first exposed to the no-interresponse interval condition. Group 2 was first exposed to the 4-s interresponse interval condition. Subjects were then exposed to the different interresponse interval conditions. There was little change in variability across conditions. However, the variability observed in the subjects first exposed to the 4-s interresponse interval was greater than the variability observed in subjects first exposed to no-interresponse interval. There was higher-order response patterning in both groups, but it was more pronounced in the no-interresponse interval group.