Melloration and maximization of reinforcement minus costs of behavior.
Pigeons (and often humans) pick the locally better schedule even when it cuts total payoff — a bias you can override with clear cues and training.
01Research in Context
What this study did
Herrnstein gave pigeons two keys. Pecking either key paid food on variable-interval schedules.
He then added a twist: limited-hold windows. If the bird did not peck within the window, that reinforcer was lost.
The windows were placed on the rich side only, then on the lean side only, to see if birds still "matched" time to payoff rate.
What they found
When the hold was on the rich side, birds moved even more time there. They overshot matching.
When the hold was on the lean side, birds still hugged the rich key. They earned less food overall.
The birds chased local better payoff, not the highest possible total. This is melioration, not maximization.
How this fits with other research
Mansell et al. (2002) later repeated the pattern with adult humans choosing computer points. People also under-matched and meliorated, showing the rule crosses species.
Steege et al. (1989) seems to disagree. Their humans, working for money, picked the option that gave the highest total dollars — true maximization. The gap is explained by the reinforcer: money lets humans calculate, while pigeon grain or game points pull reflexive approach.
Winett et al. (1991) adds a bridge. After teaching humans to notice the ratio requirement, their choices slid from matching toward maximizing. Training, not species, decides which rule wins.
Why it matters
Your clients may meliorate, too. A child might stay at the easy task that pays one token fast instead of switching to the task that pays five tokens later.
To get maximization, first teach the learner to see the long-term rate. Use prompts, counters, or brief delays that make the richer schedule obvious. Then fade the cues so the better choice persists.
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Join Free →Put a 3-s colored cue on the leaner, higher-pay side of your token board and prompt the first two switches; watch if the learner starts choosing that side more often.
02At a glance
03Original abstract
Eight pigeons were exposed to independent concurrent schedules. Concurrent variable-interval 60-second variable-interval 60-second schedules were presented to one group of four subjects. Following baseline training, a limited hold was added to one of the schedules and the duration of the hold was decreased in successive conditions. Concurrent variable-interval 120-second variable-interval 40-second schedules were presented to another group of four subjects. These subjects were first exposed to decreasing durations of a limited hold in the variable-interval 40-second component. After replication of the baseline, a limited hold in the variable-interval 120-second component was decreased in duration. The initial durations of the holds were determined from the subjects' responding in the baseline conditions. A duration was chosen such that approximately 25% of the scheduled reinforcers would be canceled if responding remained unchanged.Approximate matching of time proportions and reinforcement proportions was observed when the limited hold was added to the variable-interval 60-second schedule and when the limited hold was added to the variable-interval 40-second schedule. Time proportions were less extreme than reinforcement proportions when the limited hold operated in a variable-interval 120-second schedule. Overall reinforcement rates tended to decrease with continued training in concurrent schedules with a limited hold. Absolute deviations from time matching also decreased. The results provide evidence against the principle of reinforcement maximization, and support Herrnstein and Vaughan's (1980) melioration hypothesis.
Journal of the experimental analysis of behavior, 1984 · doi:10.1901/jeab.1984.42-113