The effect of contingency upon the appetitive conditioning of free-operant behavior.
Contingency itself—not just contiguity—controls free-operant response rate; local probability programming gives us a cleaner way to show it.
01Research in Context
What this study did
Researchers used a lever-press setup with rats. They changed the local chance that a press produced food. The chance slid from 100% down to 0% and even into the negative range. Each change lasted until responding stabilized. The goal was to see if the response-food link itself, not just timing, controlled how fast the rats pressed.
What they found
Press rates dropped in a clean line as the contingency shrank. When food became random or anti-correlated with pressing, rates fell toward zero. The result shows contingency acts like a volume knob: turn it down and behavior fades.
How this fits with other research
Kuroda et al. (2018) repeated the idea with humans and kept timing fixed. Behavior still rose when the response-rate to reinforcement-rate correlation was positive. The 1980 animal data and the 2018 human data line up — contingency, not contiguity, drives the response.
Lattal (1974) did an earlier cousin study. They mixed free food with response-dependent food and saw the same downward slope. Hammond (1980) sharpened the picture by using local probability steps instead of mixed schedules, giving a clearer dose-response curve.
DByiers et al. (2025) extend the story in mice. They show reinforcement rate controls behavior during a cue, while probability controls behavior after the cue. The 1980 paper set the stage by proving probability alone can steer free-operant rate; 2025 unpacks how rate and probability split the work.
Why it matters
You now have a simple lever: the tighter the response-reinforcer link, the stronger the behavior. If a client’s responding fades, first check whether reinforcement is still truly tied to the target response. Remove accidental free reinforcers and restore a positive contingency before you tweak timing or magnitude.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Audit one client’s session for accidental free reinforcers; put every token, praise, or break back under a clear response requirement for one day and track the rate change.
02At a glance
03Original abstract
The problem of maintaining independence between response rates and reinforcement probabilities when determining the effect of varying the response-reinforcement contingency upon free-operant behavior was solved by programming local reinforcement probabilities for response and no response on a second-by-second basis. Fifty-seven rats were trained to lever-press on schedules of water reinforcement involving different values of contingency. All rats were first trained on a high positive contingency and then shifted to less positive, zero, or negative contingencies. Under these conditions, rate of lever-pressing declined appropriately when the contingency between response and reinforcement decreased or was made negative. The decline in rate produced by a zero contingency cannot be attributed to extinction, since the probability of reinforcement given the occurrence of a response was the same as for the positive contingency from which the shift to zero was made. That is, there was no change in the opportunity for response-reinforcement contiguity. It was concluded that the technique of programming local reinforcement probabilities offers promise for more critical examinations of the effects of contingency upon free-operant behavior.
Journal of the experimental analysis of behavior, 1980 · doi:10.1901/jeab.1980.34-297