If students believe that concepts are being forced upon them, they might become uncomfortable and fearful. A barrier is created by a tone of threat in the classroom. Therefore, an open, friendly environment in which trust is developed is essential in the classroom. Fear of retribution for not agreeing with a concept should be eliminated. A classroom tone of support helps to alleviate fears and encourages students to have the courage to explore concepts and beliefs that vary from those they bring to the classroom. Also, new information might threaten the student's concept of him- or herself; therefore, the less vulnerable the student feels, the more likely he or she will be able to open up to the learning process.