Interlocking schedules of reinforcement.
Gradually shifting from fixed-ratio to fixed-interval keeps break-and-run responding stable across species.
01Research in Context
What this study did
BERRYMAELLIOTT et al. (1962) built a single lever for lab rats.
The lever switched from fixed-ratio 36 to fixed-interval 2 s.
One schedule melted into the other across the session.
The team watched how pause and burst changed along the blend.
What they found
The rats gave clean break-and-run patterns.
Pause length and burst speed slid smoothly as the lever moved from ratio to interval control.
No sudden jumps appeared; the change was steady and predictable.
How this fits with other research
Rider (1977) ran the same blend but added two extra levers.
One lever paid on a matched variable-ratio, the other on a matched variable-interval.
Only the interlocking FR-FI lever kept the break-run shape, proving the pattern is special to the blend, not just any schedule.
Rapport et al. (1982) later moved the idea to college students pressing buttons.
People also shifted their pace when the FR-FI mix changed, showing the animal rule travels to humans.
Lea (1976) pushed further by letting the ratio grow inside the interval.
Moderate add-ons sharpened pauses, but big ratios broke the pattern, setting a safety line for clinicians.
Why it matters
You can shape smooth work-to-rest cycles by sliding from ratio to interval demands.
Start a new task with a short ratio, then slowly stretch the interval to build steady pacing.
Watch for ratio strain if the response count climbs too high; back off before behavior breaks.
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Join Free →Begin a task at FR 5, then add 1 s of FI after each reinforcer until you hit FI 10 s, and note if the learner keeps steady bursts.
02At a glance
03Original abstract
Four male pigmented rats were exposed to a procedure designed to investigate the relation between several performance measures and a schedule continuum ranging from FR 36 to FI 2 through four intermediate interlocking schedules. On all schedules, each subject developed a stable performance that was generally break-and-run. Analysis of the cumulative records, post-S(R) breaks, and running rates showed a continuum of performance related to the schedule continuum.
Journal of the experimental analysis of behavior, 1962 · doi:10.1901/jeab.1962.5-213