Differentiation of press durations with upper and lower limits on reinforced values.

Kuch (1974) worked with rats in a small lab cage. Each rat had a metal lever.

The rat earned food only if it held the lever down for a set time. Too short or too long earned nothing.

The study moved the allowed window higher or lower to see how the rats adjusted.

The rats quickly matched their press length to the reinforced window.

The middle press time tracked the lower limit like a ruler. Change the limit, change the press.

Buskist et al. (1988) later showed rats can stretch their "time horizon" when future food costs extra work. Both papers prove timing is plastic when pay-off rules shift.

Keesey et al. (1968) used rising ratio demands instead of duration rules. Together they show schedule walls—whether ratio or time—shape the same lever press in orderly curves.

Iannaccone et al. (2023) swapped rats for kids and swapped shock for problem behavior, yet the lesson holds: tighten or loosen the reinforcement boundary and the response follows.

You now have a clean model for teaching precise timing. Want a client to hold a greeting for two seconds? Reinforce only presses inside a 1.8–2.2 s window. The rat data say the child’s average will drift to your lower limit, so set that limit at the goal. Start wide, then narrow the window as accuracy improves.