Which of the following therapies operates on the assumption that what people believe influences how they act and feel?

Behavior therapy emphasizes modifying observable behaviors rather than exploring cognitive processes. This approach is based on principles of learning theory, such as conditioning, and does not focus on the individual's beliefs or thoughts. Therefore, it lacks the foundational assumption that beliefs significantly influence feelings and actions.

Adlerian therapy centers around social interest and the pursuit of individual goals within a community context. While it acknowledges the influence of beliefs on behavior, it primarily focuses on lifestyle, goals, and interpersonal relationships without emphasizing cognitive distortions as directly as CBT does.

Gestalt therapy emphasizes awareness, personal responsibility, and the present moment rather than cognitive processes. It focuses on how individuals perceive their experiences and fosters self-awareness but does not assert that beliefs are the primary drivers of behavior and emotions in the same way CBT does.