Schedule-Induced Behaviour

Abstract

This chapter discusses schedule-induced polydipsia. Two or three decades ago, psychologists interested in animal learning or behaviour were mostly busy testing rats and pigeons in Skinner boxes under various schedules of food reinforcement, in an attempt to elucidate the processes of instrumental conditioning. Rats can drink and eat, so it is not surprising that sooner or later someone put a water bottle into a Skinner box and a food tray. At the time of its discovery, this anomalous drinking was of interest for two major reasons. The occurrence of drinking is not in itself surprising, because while the rat is waiting for food it must do something, and that something might as well be drinking as any other behaviour. Besides, it is well known that rats drink prandially when food is freely available. What is surprising, however, is that given the opportunity the rat will go on drinking regularly after each pellet, for hours on end, with very little sign of satiation.