An evaluation of delay to reinforcement and mand variability during functional communication training

Muething et al. (2018) worked with four children who had autism or developmental delay. Each child was already using one mand during FCT. The team added a short wait between the mand and the reinforcer to see if the kids would try new ways to ask.

Sessions moved from no delay to a 3-second or 5-second delay. No extra teaching steps were added. The researchers counted how many different mand forms each child used and tracked any problem behavior.

Every child started using new mand topographies once the delay began. One quiet child began whispering, then spoke aloud. Another child added new signs while still using the old one.

Problem behavior results were mixed. Two kids showed no change, one dropped slightly, and one had a small uptick. Overall, the delay grew the mand toolbox without hurting safety for most.

Silbaugh et al. (2019) ran a direct follow-up. They paired a Lag 1 rule with progressive time delay and got the same boost in varied signing. Their design shows you can stack a lag schedule on top of simple delay for even more variety.

Clarke et al. (2003) set the stage. They taught people with intellectual disability to wait for bigger reinforcers by starting with no delay and stretching it slowly. Muething skips the warm-up and jumps straight to a fixed delay, yet still sees success, suggesting kids with ASD may tolerate waits better than once thought.

Perez et al. (2015) looked at mand familiarity instead of delay. They found kids stick with the old mand even when it sparks more problem behavior. Muething’s delay tactic offers a fix: keep the same reinforcer, just make the child wait a beat, and new mands pop out.

You can widen a child’s communication without extra drills or new tokens. Next time a client locks into one rote mand, insert a 3-second pause before delivering the item. Watch for any new vocal, sign, or picture attempt and reinforce it on the spot. One simple schedule tweak can build a flexible speaker.