Fixed-interval performance and self-control in infants.

The team watched babies work on a fixed-interval schedule. Every 60 seconds a short cartoon played if the baby pressed a button.

After each cartoon the babies chose: a tiny cartoon right now or a bigger cartoon after 40 more seconds. The study tracked how long each baby waited before pressing again.

Some babies paused a long time after each cartoon. Those same babies always picked the big delayed cartoon.

Babies who pressed quickly again chose the small immediate cartoon. Pause length predicted self-control.

Wacker et al. (1985) extends this picture. They ran the same FI schedule with older kids who could talk. The toddlers still showed animal-like pauses, but once children used rules their pattern shifted to flat, rule-governed responding.

Tracey et al. (1974) also extends the work. Preschool and early-elementary kids on FI schedules made error bursts right after reinforcement in a matching game. The pause-and-burst pattern holds past infancy.

Eisenmajer et al. (1998) conceptually replicates the choice task. Adults with developmental disabilities first picked the quick small reward. A progressive-delay program then taught them to wait for the larger one, showing the skill can be trained.

You now know that pause sensitivity is an early sign of self-control. When an infant or child shows long FI pauses, they are already orienting toward delayed bigger payoffs. In practice, watch for these natural pauses; they flag clients who may readily learn delay-of-reinforcement skills. For clients who press rapidly, start with brief imposed waits and stretch the delay progressively, just as Eisenmajer et al. (1998) did with adults.