Human choice on concurrent variable-interval variable-ratio schedules.
A short discrimination drill can move adult humans from matching to maximizing on mixed VI-VR schedules.
01Research in Context
What this study did
Researchers tested the adult humans on a computer task.
Two buttons gave heat-lamp warmth on different schedules.
One button paid on a variable-interval (VI) schedule.
The other paid on a variable-ratio (VR) schedule.
First block had no training.
Later blocks added discrimination training to raise VR response rates.
They tracked which button each person picked.
What they found
Without training, people chose buttons in line with how often each paid off.
This is called matching.
After training raised VR response rates, people shifted toward the VR button.
They began maximizing instead of matching.
Unlike animals, humans never used tiny local rate differences to guide choice.
How this fits with other research
Steege et al. (1989) saw the same flip: pigeons matched delays, humans maximized overall rate.
The new twist is that simple discrimination training can push humans from matching to maximizing.
Eisler (1984) showed pigeons stuck with melioration even when it hurt total payoff.
Humans, in contrast, can learn to maximize after brief training.
Mansell et al. (2002) found human groups undermatched in a different task.
This study shows an individual human can swing past matching toward full maximization.
Together, the papers say species and training history both steer choice patterns.
Why it matters
If a client picks the easy task too often, brief discrimination training on the hard task can tip the balance.
You do not need new reinforcers—just clearer signals and practice.
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02At a glance
03Original abstract
Each of 5 adult male humans sat in a 4 degrees C room where they could warm themselves by illuminating six heat lamps for 10-second periods according to a concurrent variable-interval variable-ratio schedule. Left-button presses on a response panel switched between the schedules and started a 2-second changeover delay. Right-button presses illuminated the heat lamps if assigned by the associated schedule and if the changeover delay had timed out. Panel lights identified the schedule in effect and each effective right-button press. A discrimination procedure--either a multiple variable-interval variable-ratio schedule or the presentation of each schedule individually on alternate days--preceded exposure to the choice procedure for some subjects. For subjects not exposed to a discrimination procedure prior to exposure to choice, or if such exposure failed to result in higher rates to the ratio than to the interval schedule, relative response rates matched relative reinforcement rates. However, if subjects responded at higher rates to the ratio schedule than to the interval schedule during a prior discrimination procedure, relative rates on a subsequent choice procedure deviated from matching in the direction of reinforcement-rate maximizing. In eight of 11 conditions, choice appeared to be governed by maximizing processes. In all cases, human concurrent ratio-interval performances differed from those of nonhumans in that matching was never obtained with local ratio-interval rate differences.
Journal of the experimental analysis of behavior, 1991 · doi:10.1901/jeab.1991.56-575