Sensitivity training, technique using group discussion and interaction intended to increase one's awareness of self and others and how one behaves with others. Sensitivity training takes many forms and goes by many names: encounter group, T-group, human relations, and group dynamics training. The group has 8–20 participants. The leader, who is trained in psychotherapy, establishes a psychologically safe environment and encourages participants to speak frankly about their feelings and each other, but remains neutral and outside the discussion. The participants choose the topics and direct the discussion. They examine their reactions to each other and test new ways to communicate. The goal of sensitivity training is to develop trust and improve communication and intrapersonal behavior. The techniques of sensitivity training have been applied to education and to training businesspeople. Sensitivity training was developed at the Esalen Institute, Big Sur, Calif., and was popular in the 1960s.