A Behavior Cusp is a behavior that when performed, opens up the learner to a whole new world of contingencies for reinforcement and punishment they didn’t have access to before they engaged in the behavior. This can lead the individual to display new behaviors or generalize existing repertoires in new ways without explicit teaching. An example of a behavior cusp is a baby crawling because now they can access new environments- a whole new (dangerous but exciting) world of reinforcers and potential punishers!