A behavioral cusp is any behavior change that brings an organism's behavior into contact with new contingencies that have far-reaching consequences.[1] A behavioral cusp is a special type of behavior change because it provides the learner with opportunities to access (1) new reinforcers, (2) new contingencies (3) new environments, (4) new related behaviors (generativeness[2]), (5) competition with archaic or problem behaviors, and it (6) impacts the people around the learner, and (7) these people agree to the behavior change and support its development after the intervention is removed.

The concept has far reaching implications for every individual, and for the field of developmental psychology, because it provides a behavioral alternative to the concept of maturation and change due to the simple passage of time, such as developmental milestones. The cusp is a behavior change that presents special features when compared to other behavior changes.