Food-avoidance in hungry pigeons, and other perplexities.

Researchers worked with hungry pigeons in a small lab chamber. The birds could peck a lighted key.

Each peck normally earned grain. Now the rule changed: if the pigeon pecked, food stayed away for a short time. The team watched whether this food-avoidance rule would stop the birds from pecking.

The pigeons kept pecking even when pecking delayed food. Only when all food was removed did the behavior finally stop.

The results hint that the flash of the key light, not the grain, was keeping the pecks alive.

Clark et al. (1977) later showed squirrel monkeys will press a lever to postpone food. Their careful parametric work extends the 1972 finding: postponement can maintain behavior, yet the birds here were not suppressed by the same logic.

Cowie et al. (2011) conceptually replicate the doubt about food as a true reinforcer. They saw pigeons switch keys when food merely signaled where the next food would arrive, matching the idea that stimulus change, not grain, can drive responding.

Kelly (1973) looks like a contradiction: food deprivation cut avoidance responding in rats. The difference is procedure. Deprivation changed the rats' motivation, while the 1972 study changed the contingency. Species and method explain the opposite outcomes.

If you run extinction or avoidance procedures, remember that simply withholding food may not cut behavior. The stimuli that surround the response can keep it alive. Check whether lights, sounds, or other signals are doing the real work. When you want to weaken a response, remove or change the sensory feedback, not just the edible consequence.