Time limits for completing fixed ratios.

Researchers worked with pigeons on fixed-ratio schedules. The birds had to peck a set number of times to earn food.

Each ratio had a time limit. If the bird finished too slowly, the trial ended and no food appeared.

The pigeons learned to hit the time window. They shortened long pauses and sped up slow peck runs.

The birds treated the time rule like any other schedule requirement. They adjusted pause and run length to match the limit.

Killeen (2023) shows that richer schedules build momentum. Here, the time limit acted like a leaner schedule, cutting the long pauses momentum can create.

Flory et al. (1974) used DRL schedules to stretch response times. Both studies prove pigeons can stretch or squeeze their timing when the schedule demands it.

Farmer et al. (1966) placed stimuli at different points in fixed-interval schedules. Their work helps explain how the pigeons knew when to start running: internal cues from elapsed time served the same function.

If you add a time cap to any fixed-ratio program, clients will likely speed up. Use this to reduce long off-task pauses during seat-work or chores. Start with a generous limit, then tighten it slowly while keeping the ratio count the same. Watch for accuracy drops—if speed rises but errors spike, fade the limit back out.