Choice and number of reinforcers.
Immediate timing beats total amount when you want behavior to stick.
01Research in Context
What this study did
Scientists watched pigeons peck two keys in a lab. Each key led to a short chain of events ending with food.
The team changed how many food rewards each chain could give. They recorded which key the bird picked.
What they found
Birds did not count the total food. They looked at the tiny gaps between snacks.
A shorter wait to the next bite, even in the richer chain, pulled the pigeon’s choice.
How this fits with other research
Millard (1979) ran the same year with the same birds and cages. That paper added a quick blackout between keys and showed the blackout cleaned up messy switching. Together, the pair proves local timing runs the show.
Ploog (2001) later kept the timing equal but made one side drop a bigger pile of food. Pigeons still went for the larger pile. Timing rules, yet amount can still win if time is tied.
Gureghian et al. (2020) moved the idea to kids with autism. They let children pick a toy AFTER a correct response, not before. Skills grew faster with the post-response choice, echoing the power of moment-to-moment events.
Why it matters
For your clients, the next second counts more than the next ten minutes. Deliver the reinforcer right after the target response, and keep the gap to the next reward short. If you must give larger rewards, place them soon or they may lose their pull.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Shrink the seconds between response and reinforcer before you increase the size of the reward.
02At a glance
03Original abstract
Pigeons were exposed to the concurrent-chains procedure in two experiments designed to investigate the effects of unequal numbers of reinforcers on choice. In Experiment 1, the pigeons were indifferent between long and short durations of access to variable-interval schedules of equal reinforcement density, but preferred a short high-density terminal link over a longer, lower density terminal link, even though in both sets of comparisons there were many more reinforcers per cycle in the longer terminal link. In Experiment 2, the pigeons preferred five reinforcers, the first of which was available after 30 sec, over a single reinforcer available at 30 sec, but only when the local interval between successive reinforcers was short. The pigeons were indifferent when this local interval was sufficiently long. The pigeons' behavior appeared to be under the control of local terminal-link variables, such as the intervals to the first reinforcer and between successive reinforcers, and was not well described in terms of transformed delays of reinforcement or reductions in average delay to reinforcement.
Journal of the experimental analysis of behavior, 1979 · doi:10.1901/jeab.1979.32-51