Multiple schedules: effects of the distribution of reinforcements between component on the distribution of responses between conponents.
Response allocation follows a simple power curve based on relative reinforcement rates.
01Research in Context
What this study did
Researchers placed pigeons in a box with two keys. Each key followed its own VI schedule.
The birds earned grain for pecks. The team varied how much grain each side paid.
They counted every peck to see how the birds split their work between the two keys.
What they found
The birds’ peck ratio matched the grain ratio, but with a twist.
For every three extra grains on one side, the birds added only one extra peck.
Total pecks also grew slowly as total grain rose.
How this fits with other research
Nigro (1966) first showed pigeons shift pecks when grain odds change. G et al. added the exact math: a one-third power curve.
Rilling et al. (1969) found the same curve holds when you measure time instead of pecks. The rule is general.
Kydd et al. (1982) later showed the switch itself predicts the ratio. The moment the bird hops left or right locks in the match.
Why it matters
You now have a ruler. Count how many reinforcers each choice delivers, take the cube root, and you can forecast how a client will split responses. Use this when balancing reinforcement across tasks in a concurrent schedule. If the math drifts, check for hidden reinforcers or timing issues.
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02At a glance
03Original abstract
Two pigeons were trained to peck a key under several multiple variable-interval variable-interval schedules of reinforcement; different numbers of reinforcements were scheduled in two components of equal duration which were correlated with red and green illumination of the response key respectively. The results showed: (1) that the total number of responses in a session was proportional to the one-sixth power of the total number of reinforcements delivered in that session; and (2) that the ratio of responses between the two components was equal to the one-third power of the ratio of reinforcements between them. This latter exponent may be regarded as reflecting the sensitivity of the distribution of responses between the components to the distribution of reinforcements. It was suggested that the effects of a number of complex schedules of reinforcement could be summarized by different values of this exponent.
Journal of the experimental analysis of behavior, 1968 · doi:10.1901/jeab.1968.11-517