Answer:
positive reinforcement. Positive reinforcement is a technique used in behavioral psychology to encourage and strengthen desirable behavior by providing a positive consequence immediately following the behavior. In this case, Nicholas is being reinforced for smoothing his sheets, tucking them in, and pulling the comforter up to the top of the bed, which increases the likelihood that he will continue to engage in these behaviors in the future. The positive reinforcement is the reward Nicholas receives for his behavior, which is likely something he finds enjoyable or desirable, such as praise, attention, or some other form of positive feedback from his RBT. By reinforcing positive behaviors, the RBT is helping to shape Nicholas's behavior in a positive way and encouraging him to continue to engage in these behaviors in the future.