Sensitivity to relative reinforcer rate in concurrent schedules: independence from relative and absolute reinforcer duration.
Food size does not change how fast behavior follows rate shifts—rate is the lever.
01Research in Context
What this study did
Researchers watched pigeons peck two keys. Each key gave food on its own timer.
They kept the food timers the same but changed how long each food hopper stayed open.
The question: does bigger food make birds switch keys faster when the timers change?
What they found
Birds still matched their pecks to the timer ratios, no matter how big the food was.
Short food, long food—sensitivity to rate stayed the same.
How this fits with other research
Oliver et al. (2002) saw the same matching rule in kids with severe problem behavior.
That study shows the lab rule holds in living rooms, not just cages.
Shimp et al. (1971) first proved brief schedule parts still let matching happen.
Together they say: rate drives choice, while size and setting matter less.
Why it matters
When you adjust reinforcement schedules, focus on the rate, not the size. A tiny candy every minute can shape behavior as well as a big cookie every minute. Keep the pace steady and let the magnitude stay simple.
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02At a glance
03Original abstract
Twelve pigeons responded on two keys under concurrent variable-interval (VI) schedules. Over several series of conditions, relative and absolute magnitudes of reinforcement were varied. Within each series, relative rate of reinforcement was varied and sensitivity of behavior ratios to reinforcer-rate ratios was assessed. When responding at both alternatives was maintained by equal-sized small reinforcers, sensitivity to variation in reinforcer-rate ratios was the same as when large reinforcers were used. This result was observed when the overall rate of reinforcement was constant over conditions, and also in another series of concurrent schedules in which one schedule was kept constant at VI ached 120 s. Similarly, reinforcer magnitude did not affect the rate at which response allocation approached asymptote within a condition. When reinforcer magnitudes differred between the two responses and reinforcer-rate ratios were varied, sensitivity of behavior allocation was unaffected although response bias favored the schedule that arranged the larger reinforcers. Analysis of absolute response rates ratio sensitivity to reinforcement occurrred on the two keys showed that this invariance of response despite changes in reinforcement interaction that were observed in absolute response rates on the constant VI 120-s schedule. Response rate on the constant VI 120-s schedule was inversely related to reinforcer rate on the varied key and the strength of this relation depended on the relative magnitude of reinforcers arranged on varied key. Independence of sensitivity to reinforcer-rate ratios from relative and absolute reinforcer magnitude is consistent with the relativity and independence assumtions of the matching law.
Journal of the experimental analysis of behavior, 2001 · doi:10.1901/jeab.2001.75-25