Polydipsia induced in the rat by a second-order schedule.

Rosenblith (1970) put rats on a second-order schedule. Every minute they could earn food. A brief light flash came before each pellet.

The team watched if the rats drank water when the light blinked, even when no food arrived yet. They also tested bigger pellets.

The rats began to drink right after the light, not only after eating. The tiny light had become a drink cue.

Larger pellets made both bar pressing and drinking rise together.

Hymowitz et al. (1974) later added electric shocks. Response-independent shocks cut the water drinking, but shocks that the rat could control did not. This shows the same polydipsia is fragile to random aversive events yet tough when the rat has control.

Hymowitz (1976) varied shock timing and body weight. He found that lighter, hungrier rats kept drinking despite shock. Together these studies extend Z’s baseline by mapping when adjunctive drinking survives or folds under punishment.

Azrin et al. (1967) used the same fixed-interval food schedule but produced aggressive pecking in pigeons instead of drinking. The schedule structure stays; the species and the extra behavior change.

You now know neutral stimuli inside a chain can gain control over adjunctive behavior. If a client engages in odd repetitive acts during breaks, check what cues come right before. Change the cue, change the timing, or give the client control over tiny choices. These levers may cut the behavior without any punishment at all.