Cognitive behavioral therapy (CBT) focuses on changing cognitions and behaviors to produce desired changes. Rational emotive behavioral therapy (REBT), an approach to CBT, teaches that emotions stem from beliefs about life situations. According to REBT, people contribute to their own problems through irrational beliefs containing "shoulds", "musts", and "awfulizing". REBT disputes irrational beliefs using logic to challenge unrealistic hypotheses and detect, debate, and discriminate between rational and irrational beliefs.