An inexpensive token.

Wahler (1969) tested a hardware hack. The author wanted a token that felt real but could not buy candy outside the clinic.

The team chose Mexican five-centavo coins. They checked size, weight, and vending-machine fit. The coins worked in homemade token slots but jammed in standard U.S. candy machines.

The coins passed the clinic test. They were cheap, easy to buy in bulk, and stayed in-program. Staff could hand them out like money without worrying about kids spending them on real treats.

Fernandez et al. (2023) show most BCBAs today skip key token-economy steps. They often use stickers or points that have no real feel. Wahler (1969) gives the opposite advice: use something that clinks.

Ivy et al. (2017) found only 19 % of published token studies give full hardware details. The 1969 note fills that gap. It is the missing parts list older reviews left out.

Kaiser et al. (2022) report large gains when tokens are backed by solid reinforcers. Wahler (1969) adds a cheap way to keep tokens from leaking into the real economy.

You can still buy centavos online for a few cents each. Next time you set up a token board, drop real coins in a coffee can. The sound and weight boost conditioned reinforcement, and they won’t work in the hallway vending machine. It’s a fifty-year-old hack that still saves money and keeps your tokens where you want them—in your session.