ABA Fundamentals

VARIABLES DETERMINING THE EFFECTS OF DELAY IN REINFORCEMENT.

FERSTER et al. (1965) · Journal of the experimental analysis of behavior 1965
★ The Verdict

Big reinforcers plus clear cues keep fixed-ratio responding alive across 24-hour delays—no gradual fade needed.

✓ Read this if BCBAs who use token boards, point systems, or ratio schedules in clinics, schools, or homes.
✗ Skip if Practitioners who deliver reinforcement within seconds and never face overnight gaps.

01Research in Context

01

What this study did

The team tested if rats would keep pressing a lever for food when the snack arrived a full day later.

They varied three things at once: how long the wait was, how big the food pile was, and how many presses the rat had to do.

By mixing these pieces they found the sweet spot that kept the lever pressing alive even with 24-hour delays.

02

What they found

Big food pellets plus clear lights and sounds kept the rats working through huge ratios and next-day payoff.

No slow fading was needed; the animals jumped straight into the long-delay game when the reward was large and the cues were tight.

03

How this fits with other research

Findley et al. (1965) boosted big-ratio work by adding clicker tokens mid-run; B et al. now show the same ratios can hold if you skip mid-ratio cues and just make the final snack bigger.

de Carvalho et al. (2018) later moved the ratio idea into two rats working together, proving FR and VR schedules still pump steady effort even when the task is social.

Barrett et al. (1987) found variable rules keep a rat holding a lever longer; the 1965 study adds that variable delay plus large payoff keeps the whole ratio chain intact across a day.

04

Why it matters

You can stretch reinforcement delays without fading if you give a big reward and keep the stimulus tight.

Try pairing a large, preferred item with a clear signal when your learner finishes a long work chunk.

This move can buy you overnight or weekend gaps in token boards, school jobs, or fitness apps without losing momentum.

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→ Action — try this Monday

End a tough session with a double-size reward and a special sound; tell the learner the next payout comes after tomorrow’s first task and watch the work rate hold.

02At a glance

Intervention
other
Design
single case other
Population
not specified
Finding
positive

03Original abstract

Procedures were discovered for maintaining a small fixed-ratio performance under 24-hr delay in reinforcement, by appropriate manipulation of the length of delay, amount of food delivered, and size of the fixed ratio. Other experiments showed that (1) the parameters discovered in the first experiment could produce the same result without the complex history of the first procedures; (2) the same parameters of the delayed-reinforcement procedure could maintain an explicit chain of responses; (3) gradual increase in the delay in reinforcement from small to large values was not a necessary condition for achieving the major result, if large amounts of food were delivered as reinforcement and all of the behaviors were first under good control of the relevant stimuli with short delays.

Journal of the experimental analysis of behavior, 1965 · doi:10.1901/jeab.1965.8-243