Aversive aspects of a schedule of positive reinforcement.
Large fixed-ratio schedules can feel aversive and trigger escape or aggression even while reinforcement still arrives.
01Research in Context
What this study did
MIGLELong (1963) worked with pigeons in a small lab box.
The birds had to peck a key many times to earn food.
The required number kept rising: 50, 100, 200 pecks.
The researcher also gave the birds a second key.
Pecking this key changed the lights for a moment.
He counted how often the birds hit this change-key as the work load grew.
What they found
When the ratio reached 200 pecks, the birds pecked the change-key more.
They still earned food, but they acted as if they wanted a break from the task.
This early sign of ratio strain showed up even though food kept coming.
How this fits with other research
Dardano (1970) later saw the same high-ratio birds attack a target bird instead of a plastic key.
Both papers point to the same takeaway: big ratios feel bad and can spark new, sometimes harmful, responses.
Halpern et al. (1966) added detail by timing the pause after each food delivery.
They showed the pause grows longer as the ratio climbs, backing the idea that large ratios are aversive.
Gettinger (1993) then split each ratio into pause time and active pecking.
The downturn in total responses vanished when the pause was removed, showing the pause, not laziness, drives the strain.
Waite et al. (1972) stretched the idea to fixed-interval schedules and saw aggression rise after food, proving the aversive effect is not limited to ratio schedules.
Why it matters
Watch for extra requests for breaks, fidgeting, or sudden problem behavior when you raise response requirements.
These may be early signs of ratio strain, not mere non-compliance.
Split your data into post-reinforcement pause and active work time to see which part is growing.
If the pause is stretching, lower the ratio or add brief leisure before the next demand to keep the task pleasant.
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Join Free →Record the pause after each reinforcer; if it keeps growing, insert a 5-10 second break or lower the ratio requirement.
02At a glance
03Original abstract
Six male White Carneaux pigeons were trained to peck at one of two keys to obtain food on several fixed-ratio schedules of reinforcement. Concurrently, the first response on a second key could, I-change the conditions of visual stimulation and remove the food reinforcement contingency, II-change the conditions of stimulation and have no effect upon the reinforcement contingency, or III-do nothing. The second response on the stimulus change key always restored baseline conditions. When second-key responses produced a stimulus change, the number of such responses was a function of the ratio value on the first key. Typically, second-key responses occurred before the start of fixed-ratio runs. The duration of stimulus change periods was an exponential function of the number of responses required for reinforcement when the possibility for reinforcement was not disturbed by periods of stimulus change (Condition II).
Journal of the experimental analysis of behavior, 1963 · doi:10.1901/jeab.1963.6-423