The problem was to evaluate the self-concept differences revealed in the personality profiles of underdeveloped junior high school boys who had been participating in a special non-competitive program of physical education. Five subproblems were explored. The underdeveloped boys were compared with junior high athletes for personality differences. A random sample of the undeveloped boys received additional verbal encouragement from the instructor to see if further personality changes were evident. Results indicate that allowing physically underdeveloped boys to participate in an environment using self-based evaluation standards rather than competitively based standards contributed to gains in emotional security and sense of personal worth. The recommendations of the study are that further research be conducted in the area of self-evaluation uses in more standard academic curricular subjects which may lend themselves to self-evaluation. (Author/LAA)