Self-inhibiting effects of reinforcement.

Catania (1973) wrote a theory paper. It asked: what happens to other responses while one response earns reinforcement?

The author proposed that every reinforcer has two jobs. It excites the response it follows, and it quietly inhibits everything else happening at the same time.

The paper did not collect new data. Instead it showed how the inhibitory idea explains puzzling results from older experiments.

If the idea is right, then reinforcers are like spotlights. They brighten one path and dim the rest.

Hall (1992) later tested kids in a classroom token system. When reinforcer quality differed between tasks, the matching law broke down. Unequal quality seems to add extra inhibition or extra pull, just as Catania (1973) predicted.

Smith et al. (1997) ran preference assessments with food and leisure items. Food items pushed leisure items out of the rankings. This displacement is a real-world example of food reinforcers inhibiting concurrent choices.

Carter et al. (2020) found the displacement does not always mean weaker power. Three of seven kids worked just as hard for displaced leisure items. The inhibitory effect hides potency, so you must test, not just rank.

When you run concurrent schedules, watch for hidden suppression. A reinforcer that looks weak may be blocked by a stronger one sitting next to it. Always assess potency after you see displacement. Swap tasks, hide edibles, or run separate trials. The spotlight idea helps you design cleaner assessments and truer matching analyses.