Effects of different delay of reinforcement procedures on variable-interval responding.
Even signaled delays longer than a few seconds cut response rates—deliver reinforcement immediately.
01Research in Context
What this study did
Davis et al. (1972) worked with lab rats on a variable-interval schedule.
A cue light came on right after each bar press. Food followed 10, 30, or 100 seconds later.
They also tested what happened if extra VI schedules ran during the wait time.
What they found
Longer signaled waits cut response rates. Pauses after food grew too.
Extra schedules during the delay did not change the main VI pattern.
The take-home: even a 30-second signaled gap weakens behavior.
How this fits with other research
Xue et al. (2024) and Majdalany et al. (2016) saw the same slow-down in kids with autism. Their tact trials showed 6–8 s delays already hurt learning. The 1972 rat curve lines up with the child data: short waits matter across species.
Corrigan et al. (1998) removed the cue light. Pigeons then stared at the feeder instead of pecking. Together the two papers show: a signal helps, but the delay still hurts.
Barnard et al. (1977) found autoshaped pecking died when response-food time topped 4 s. H et al. saw the rat drop-off near 10–30 s. The numbers differ, yet both warn: keep the gap tight.
Why it matters
Deliver the reinforcer right after the target response. If you must wait, keep it under 5 seconds. This holds for rats, pigeons, and children with autism. Use a signal if a delay is unavoidable, but still aim for zero delay. Check your session data: falling rates may trace to hidden wait times inside your schedule.
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02At a glance
03Original abstract
Two experiments studied responding in the rat when the first bar press after a variable period of time produced a cue light that remained on for either 10, 30, or 100 sec and terminated with the delivery of food. In Experiment I, response rate decreased and time to the first response after reinforcement increased as the delay of reinforcement increased. Similar results were obtained whether the delay consisted of retracting the lever during the delay, a fixed delay with no scheduled consequence for responding, or every response during the delay restarted the delay interval. In Experiment II, fixed-delay and fixed-interval schedules of the same duration during the delay period had no differential effect on either response rate or time to the first response after reinforcement, but differentially controlled responding during the delay periods.
Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.18-141