Matching and maximizing with concurrent ratio-interval schedules.
Take away downtime and animals pick the VR-VI side that pushes both schedules ahead—clear maximization.
01Research in Context
What this study did
Wallander et al. (1983) set up two schedules side by side. One paid off after a set number of responses. The other paid off after the first response in a time window.
They removed anything that let the animal loaf between responses. Then they watched which side the animal picked.
What they found
When downtime was gone, the animals shifted toward the key that moved both schedules forward. The choice fit a maximize-reinforcers rule, not a simple match-rates rule.
How this fits with other research
Fovel et al. (1989) ran almost the same VR-VI setup with mice and also saw maximization. The 1983 result held up across species.
Savastano et al. (1994) tried the same VR-VI arrangement with adult humans. People only leaned toward the ratio side; they did not fully maximize. The animal finding extends to humans, but the effect is weaker.
Yuwiler et al. (1992) used VI-VI schedules and saw no maximization at all. The positive maximization result seems tied to the VR-VI mix, not to every concurrent schedule.
Why it matters
If you run concurrent schedules in a token economy or choice assessment, strip out dead time. Once leisure cues are gone, clients may shift toward the option that speeds overall payoff. Try cutting wait time between tasks and watch whether the learner’s preference moves to the richer, faster track.
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02At a glance
03Original abstract
Animals exposed to standard concurrent variable-ratio variable-interval schedules could maximize overall reinforcement rate if, in responding, they showed a strong response bias toward the variable-ratio schedule. Tests with the standard schedules have failed to find such a bias and have been widely cited as evidence against maximization as an explanation of animal choice behavior. However, those experiments were confounded in that the value of leisure (behavior other than the instrumental response) partially offsets the value of reinforcement. The present experiment provides another such test using a concurrent procedure in which the confounding effects of leisure were mostly eliminated while the critical aspects of the concurrent variable-ratio variable-interval contingency were maintained: Responding in one component advanced only its ratio schedule while responding in the other component advanced both ratio schedules. The bias toward the latter component predicted by maximization theory was found.
Journal of the experimental analysis of behavior, 1983 · doi:10.1901/jeab.1983.40-217