An evaluation of time in establishing operation on the effectiveness of functional communication training.

The team ran FCT with two mand choices. One mand was already in the child’s daily routine. The other was brand-new.

They let the child pick either mand during the session. Then they watched which one the child used and how much problem behavior happened.

Kids almost always picked the mand they already knew. That old mand, however, came with more problem behavior.

Even when the new mand worked just as well, the children stayed with the familiar one.

Lancioni et al. (2009) said to pick the mand the child already does best. Perez et al. (2015) show that the best-known mand can also spark more problem behavior. The two papers seem to clash, but the gap is timing. E et al. looked at skill level before FCT starts; M et al. looked at what happens after the old mand has a long history of reinforcement.

Muething et al. (2018) later showed that adding a short delay to reinforcement makes kids try new mands. That supports M et al.’s point: you have to push the learner away from the old response.

Cadette et al. (2016) found that a quick five-minute preference test can align parent and child on which mand to use. Their tool could prevent the trap M et al. found—sticking with a mand that feels safe but fuels problem behavior.

If you start FCT with the child’s favorite old mand, you may keep problem behavior alive. Instead, teach a fresh mand from day one. Run a brief preference check like Cadette et al. (2016), then build brand-new topography. Your learner gets the same reinforcer, but the history that fed problem behavior is left behind.