A STRUCTURED PHYSICAL EDUCATION PROGRAM CONSISTING MOSTLY OF BODY BUILDING EXERCISES AND WEIGHT LIFTING WAS USED TO GIVE PHYSICALLY UNDERDEVELOPED BOYS A SENSE OF PERSONAL ACCOMPLISHMENT. JUNIOR HIGH SCHOOL BOYS FROM GRADES SEVEN, EIGHT, AND NINE, CLASSIFIED ON THE BASIS OF LACK OF ATHLETIC ABILITY, WERE GIVEN THE CALIFORNIA PSYCHOLOGICAL INVENTORY (CPI) AT THE BEGINNING OF THE SCHOOL YEAR AND AGAIN JUST BEFORE THE SCHOOL YEAR ENDED. A CORRELATION MATRIX OF THE 18 CPI VARIABLES WAS SUBMITTED TO A PRINCIPLE-COMPONENT FACTOR ANALYSIS PROGRAM. A DISCRIMINANT ANALYSIS WAS MADE. THE UNDERDEVELOPED BOYS HAD SIGNIFICANT GAINS IN 10 OF THE 18 CPI SCALES. PHYSICALLY UNDERDEVELOPED BOYS WERE FOUND TO BE LESS SOCIALLY ADJUSTED, AND TO HAVE A LOWER SELF-ESTEEM AND SENSE OF PERSONAL WORTH THAN ATHLETIC BOYS. THE UNDERDEVELOPED BOYS SHOWED SIGNIFICANT GAINS, INDICATING AN INCREASE IN SOCIAL ADJUSTMENT. FURTHER STUDY INVESTIGATING THE GENERAL APPLICABILITY OF ALLOWING STUDENTS TO RELATE GROWTH TO PERSONAL ACHIEVEMENT FREE FROM EXTERNAL STANDARDS IS RECOMMEDED. (AUTHORS/PS)