Stimulus control in the experimental study of cooperation.

Two adults sat in a small lab room. Each had a button and a light.

If both pressed within three seconds after the lights flashed, they earned coins. If either was late, both got a boring timeout.

The researchers added or removed two social cues: a red light that told whose turn it was next, and a buzzer that counted down the last second. They wanted to know if cooperation needed these extra signals.

With both cues on, the pair hit the three-second window almost every time.

When the cues were removed, cooperation crashed. Partners stopped watching each other and many trials timed out.

Bring the cues back and team success bounced back. The social signals, not just the money, controlled working together.

Reid et al. (2005) later showed the same rule in preschoolers. Once kids learned to raise a hand only when a green card was up, the card could be taken away and the hand-raising still happened. Both studies prove social cues can lock in behavior, then fade.

WEISSMAN (1963) found the opposite timing effect with pigeons. Short limited-hold windows broke stimulus control. R et al. used a very tight three-second hold, yet control stayed strong because the added social lights and buzzer made the deadline obvious. Same short window, different outcome—method explains the gap.

Herrnstein et al. (1979) warn that learners may latch onto the wrong prompt. Their size-fading failed when kids only saw brightness. R et al. avoided this trap: the red light and buzzer were part of the cooperative response, not extra prompts, so partners attended to the right thing.

When you run social skills groups, job-coach pairs, or peer tutoring, build in clear partner cues—hand raise, click, name card—tied to the shared goal. After the team wins a few rounds, try dropping the cue. If cooperation falls apart like it did here, the cue is still teaching; put it back and thin it more slowly. This keeps social behavior under natural, not artificial, control.