Behavioral momentum. Implications and development from reinforcement theories.

Cameron et al. (1996) wrote a theory paper. They asked, "Why do some behaviors keep happening even when they no longer pay off?"

They borrowed the physics idea of momentum. A heavy ball keeps rolling after you stop pushing. A well-fed behavior keeps going after you stop the reinforcers.

The paper lays out math to predict how hard it will be to stop a behavior. It says we should measure persistence, not just how often the behavior happens.

The model says three things set persistence: how rich the past pay-off was, how often it came, and how steady the background rewards are.

Rich, steady histories make behavior "heavy." It will take more time, more prompts, or stronger penalties to slow it down.

Pritchard et al. (2014) took the same idea and aimed it at treatment relapse. They say problem behavior returns because its momentum was never thinned; you just put it on a diet too fast.

Williams (1996) published the same year with a cousin idea called fluency. Both papers tell us to look past simple counts. Momentum cares about resistance to change; fluency cares about speed plus keeping the skill later.

Williams et al. (2002) looked at the opposite side: variability. They show novelty is just variation under stimulus control. Together these papers give a fuller picture—behaviors can be steady, sticky, or flexible, and we can plan for each.

Next time you write a behavior plan, add a momentum check. Ask, "How rich is this behavior's history?" If the history is thick with rewards, thin them slowly and pump up the replacement behavior first. This small shift can save you from the "it worked for a week, then it came back" trap.