Behavioral cusps: a developmental and pragmatic concept for behavior analysis.
Target behavioral cusps—skills that unlock entire new learning environments—to multiply intervention impact.
01Research in Context
What this study did
Shearn et al. (1997) wrote a theory paper. They asked, "Which single behaviors open whole new worlds for a learner?"
They coined the term "behavioral cusp." A cusp is a small skill that, once learned, exposes the person to brand-new reinforcers and environments.
The paper gives no data. It maps the rules for spotting these high-leverage skills.
What they found
The authors list six signs of a cusp. The key sign: after the skill appears, the person can now learn many other things without extra teaching.
Example: learning to read a few words lets a child access library books, homework, and street signs. Reading is a cusp; each new word is not.
How this fits with other research
Becker et al. (2024) pick up where J et al. left off. They add a step-by-step schema that shows how to plan for cusps in today’s culturally diverse clinics.
Crossman et al. (1985) also chase high-leverage change, but they use feedback loops inside one person. Cusps look outward: one skill opens new outside contingencies.
Paliliunas (2022) says we should pick targets that match client values. Cusps give you the technical lens for choosing which valued targets will ripple the farthest.
Why it matters
Stop teaching every tiny skill on the list. Instead, test if a skill is a cusp. If it is, pour your hours there. One mastered cusp can replace weeks of later drills and give the client whole new social and learning playgrounds.
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Join Free →Look at your client’s next goal. Ask, "If they master this, will new reinforcers and settings suddenly become available?" If yes, keep it. If no, swap it for a cusp.
02At a glance
03Original abstract
Most concepts of development explain certain behavior changes as products or markers of the invariable succession of emerging periods, stages, refinements, or achievements that define and order much of an individual's life. A different but comparable concept can be derived from the most basic mechanisms of behavior analysis, which are its environmental contingencies, and from its most basic strategy, which is to study behavior as its subject matter. From a behavior-analytic perspective, the most fundamental developmental questions are (a) whether these contingencies vary in any systematic way across the life span, and thus make behavior change in a correspondingly systematic way; (b) whether some of these contingencies and their changes have more far-reaching consequences than others, in terms of the importance to the organism and others, of the behavior classes they change. Certain behavior changes open the door to especially broad or especially important further behavior change, leading to the concept of the behavioral cusp. A behavioral cusp, then, is any behavior change that brings the organism's behavior into contact with new contingencies that have even more far-reaching consequences. Of all the environmental contingencies that change or maintain behavior, those that accomplish cusps are developmental. Behavior change remains the fundamental phenomenon of development for a behavior-analytic view; a cusp is a special instance of behavior change, a change crucial to what can come next.
Journal of applied behavior analysis, 1997 · doi:10.1901/jaba.1997.30-533