Fixed-ratio schedules of conditioned reinforcement with chimpanzees.

Scientists watched chimps work for tokens on a fixed-ratio schedule.

Each token later traded for food. The team recorded how fast the apes pressed after each payoff.

The chimps showed a clear pattern: long pause right after food, then fast steady pressing until the next payoff.

This pause-and-run rhythm became the signature picture of fixed-ratio work.

Findley et al. (1965) built on the same setup but broke big ratios into smaller chunks with extra tokens mid-way. Pauses shrank and the apes preferred the chunked version.

Tracey et al. (1974) moved the schedule to preschool kids doing matching games. The same post-reinforcement pause popped up, showing the pattern crosses species and tasks.

Hamm et al. (1978) kept the chimps and FR schedule but looked at where they pressed. Responses settled into one spot, revealing that fixed-ratio also stamps in rigid response topography.

If you run token boards or point systems, expect a brief lull right after each payoff. Inserting small bonuses mid-ratio, like D et al. did, can cut that pause and keep momentum. Try delivering a "half-way" token or praise to smooth large-ratio tasks with your learners.