Roger T. Kelleher, behavior analyst.

Branch (2006) wrote a short tribute to Roger Kelleher. It sums up his key papers from the 1950s and 1960s.

The piece does not test new clients. It simply walks readers through Kelleher’s findings on conditioned reinforcement and schedule effects.

Kelleher showed that a neutral stimulus can become reinforc­ing if it predicts future food. This is now called a conditioned reinforcer.

He also mapped how fixed-ratio, variable-ratio, and interval schedules change response rate and pausing. These curves still appear in every BCBA textbook.

Azrin et al. (1969) put Kelleher’s ratio schedules straight into a classroom. Students with intellectual disability followed group instructions when tokens were delivered on a fixed-ratio 5 schedule. The study shows the lab work translates to real kids at desks.

Regnier et al. (2022) extends the schedule idea by adding thinning plus social praise. They found that fading the token rate while adding teacher attention keeps gains after tokens end. This builds directly on Kelleher’s early thinning data.

Kaiser et al. (2022) meta-analyzed 24 elementary token-economy studies. Large effect sizes line up with Kelleher’s claim that well-scheduled tokens are powerful. The classroom papers simply widen the scope he started.

If you run token systems, you are using Kelleher’s rules whether you know it or not. Review his original curves when you set exchange rates and thinning steps. Pair tokens with social praise from day one so you can fade tokens later without losing behavior.