Human, free-operant avoidance of "time out" from monetary reinforcement.

Researchers asked adults to press a button to keep money they had already earned.

If the adults stopped pressing, the screen flashed "time-out" and coins disappeared.

The longer the safe gap between presses, the less often people had to respond.

People kept pressing even though shocks were never used.

Response speed followed the same rules seen in animal shock-avoidance studies.

Shorter safe gaps made people press faster; longer gaps let them slow down.

Catania et al. (1966) ran the same schedule with rats and shocks. Both studies show that stretching the safe interval cuts response rate, proving the rule works across species and aversive events.

Hineline et al. (1970) later added flashing lights and tones. They found timing still happened, but it did not predict success. Together the papers show that avoidance runs on two tracks: one for rate, one for timing.

Staats et al. (2000) kept rats awake for 24 h. Sleep loss made the animals press faster, just like shortening the safe gap. The 1966 human data give a clean baseline for interpreting those fatigue boosts.

You now know that loss of any reinforcer—money, tokens, free time—can drive avoidance. When a client races through work to keep a preferred item, think "free-operant avoidance." You can slow the response cycle by lengthening the safe period or adding brief breaks, exactly the levers this study mapped out.