Elicited responding in chain schedules.

Researchers placed pigeons on two-link chain schedules. In the first link, pecks either produced food or canceled it. The second link always paid off.

They measured how often birds pecked during the first link. If pecking is only reinforced by future food, omission trials should stop it cold.

Birds kept pecking on more than a large share of omission trials. When pecks did deliver food, the rate jumped above a large share.

The schedule itself, not just future food, pulled the response out of the birds.

Michael (1974) showed that a stimulus is only reinforcing if it points to the richer schedule. Davison et al. (1991) adds that the same stimulus can also elicit responses even when it signals "no payoff."

Jones et al. (1992) later moved the idea to humans. College students pressed keys just to see words that meant "extinction coming." The pigeon elicitation effect travels across species and topographies.

Russell et al. (2018) tested tokens with children. Tokens kept kids working after they had eaten their fill, mirroring how schedule stimuli kept pigeons pecking when food was canceled. Same conditioned-reinforcement engine, new wheels.

Your client may work for tokens, praise, or lights that merely correlate with later reinforcement. This study warns that these cues can also trigger responses on their own, even when the payoff is removed or reversed. Check if the "signal" is strengthening behavior you don't want; if so, either change the signal or put the reinforcer directly on the response you do want.