Crespi effect
in conditioning, an increase (or decrease) in a response that is disproportionate to the reinforcement. This occurs when there is a sudden shift in the amount of reinforcement; for example, if the amount of food given as reinforcement is suddenly increased from 1 g to 6 g, the level of performance is higher than if 6 g of food had been the only reinforcement given. Compare behavioral contrast. [Leo P. Crespi (1916–2008), U.S. psychologist]