Tom Khanna, age 16, of Las Vegas, Nev., for his question:

WHO DEVELOPED SENSITIVITY TRAINING?

Sensitivity tiaining is a learning process designed to increase an individuals awareness of himself, other people and his environment. A German psychologist named Kurt Lewin conducted the first sensitivity training encounter group at a workshop in New Britain, Conn., in 1946. The Esalen Institute in Big Sur, Calif., developed and poularized sensitivity training in the early 1960s.

Sensitivity training takes place in a group of from eight to 20 persons, including a leader. Members of this "encounter group" speak openly about their feelings and reactions.

`Some psychologistsregard sensitivity training as a major development. They believe it can make a person more aware of his inner feelings and help him get alongmore effectively with others. Some educators use it in teaching andsome businessmen use it to learn how to work more productively with others.

Other psychologists criticize sensitivity training. They call it experimental and claim that its effectiveness has not been proved. Critics often believe that encounter groups do not take enough care to exclude people who might react badly to sensitivity training. They point out that some participants have been psychologically injured at encounter group meetings.