Separating the effects of interreinforcement time and number of interreinforcement responses.

Neuringer et al. (1968) worked with pigeons on two simple schedules. One schedule paid for a set number of pecks. The other paid for the first peck after a set time passed.

The team watched how long the bird waited before the next peck. They asked: does the wait grow because time passed, or because many pecks happened?

When the schedule was based on time, the birds waited longer as the time rule grew. When the schedule was based on peck count, the wait stayed the same even when more pecks were needed.

The pause followed the clock, not the counter.

Foster et al. (1979) later added short blackouts after off-time pecks. They saw the same rule: blackout only helped on long time schedules, not on short ones. This backs the idea that time, not peck count, drives the pause.

Okouchi (2003) and Okouchi et al. (2006) showed birds remember past pay rates. If earlier sessions paid fast, birds pecked faster now. These studies extend the 1968 finding: time rules stick in memory and shape later timing.

Davison et al. (1968), from the same lab, found local chance of pay, not overall rate, steers peck speed. Together the papers say: watch the moment-to-moment clock, not the tally board.

For your clients, set the timer, not the counter. If you want a longer pause before work starts, lengthen the fixed interval or the wait-time rule. Adding extra tasks between reinforcers will not stretch the pause. Check past reinforcement rates too; a history of quick pay can make the learner start sooner than you expect.