Fixed ratio and extinction performance of infants in the second year of life.

Researchers placed a lever inside a highchair tray. Babies about one year old could press it to earn cereal.

The team first rewarded every press, then switched to fixed-ratio schedules. Later they stopped all snacks to watch extinction.

Each infant served as their own control in a single-case design.

The babies quickly learned steady fixed-ratio pressing. When food stopped, pressing slowed and then stopped, just like animal data.

Orderly schedule control showed up in humans before they could talk.

Hineline et al. (1969) ran the same FR schedules with pigeons a few years earlier. The bird data matched the infant data, proving the principle crosses species.

Lovaas et al. (1969) took extinction out of the lab and into a treatment ward. They shut off attention for self-injury in three children with ID and saw the same response drop, showing the process works for dangerous behavior.

Miller et al. (2022) refined the idea further. They added brief extinction probes and competing-stimulus fading to thin schedules fast without resurgence, turning the basic extinction finding into a clinical tool.

Saunders et al. (2005) paired FR token delivery with a simple organizer for adults with ID. Work behavior rose and aberrant behavior fell, showing the schedule still works decades later when you add supports.

You now know that fixed-ratio schedules and extinction are basic tools that hold up from babies to adults, typical or clinical. When you write a behavior plan, you can trust these patterns. Try starting with continuous reinforcement, then thin to FR, and plan a clear extinction phase or probe if needed. The process is older than you, but it still pays.