Stimuli control of behavioral history was studied in a sample of four undergraduates who were first exposed to a multiple fixed-ratio (FR) - differential-reinforcement-of-low-rates (DRL) and then, to a multiple fixed-interval (FI) - FI. Three participants showed history effects (high and low response rates in the multiple FI components previously correlated with the FR and DRL) for no more than three sessions, and one participant during the entire test. For this participant, the stimuli correlated with the components of the multiple FI (color of the response button) were changed in 10 sessions, and his behavior became similar to that of the other three participants (no differentiation in response rates between components). These results suggest that human behavior tends to be controlled by current contingencies.
Behavioral history; stimuli control; schedules of reinforcement; humans
