THIS STUDY USED TWO INTACT CLASSES OF PUBLIC SCHOOL TRAINABLE MENTALLY RETARDED CHILDREN TO STUDY THE EFFECTS OF PHYSICAL ACTIVITIES DERIVED FROM THE DOMAN-DELACATO THEORY OF PHYSICAL AND INTELLECTUAL DEVELOPMENT. THE EXPERIMENTAL GROUP CONSISTED OF SEVEN MALES AND SIX FEMALES FROM AGE 8 TO 18 AND THE CONTROL GROUP CONSISTED OF 10 MALES AND SIX FEMALES FROM AGE 8 TO 17. ALL SUBJECTS WERE GIVEN THE FOLLOWING PRE- AND POST-TESTS--(1) A MOBILITY SCALE DERIVED FROM THE DOMAN-DELACATO DEVELOPMENTAL PROFILE, (2) THE KERSHNER-DUSEWICZ-KERSHNER REVISION OF THE VINELAND ADAPTION OF THE OSERETSKY TESTS OF MOTOR PROFICIENCY, AND (3) THE PEABODY PICTURE VOCABULARY TEST. THE EXPERIMENTAL PROGRAM WAS EXTENDED THROUGH 74 TEACHING DAYS THAT APPROXIMATED FIVE AND ONE HALF HOURS EACH AND INCLUDED ACTIVITIES CONSISTENT WITH THE DOMAN-DELACATO THEORY. FOR THE CONTROL GROUP THE CURRICULUM INVOLVED A NUMBER OF NONSPECIFIC ACTIVITIES THAT COULD GIVE OPPORTUNITIES FOR PRAISE AND ATTENTION EQUAL TO THAT RECEIVED BY THE EXPERIMENTAL GROUP. HYPOTHESIS ONE STATING THERE IS A SIGNIFICANT IMPROVEMENT IN CREEPING AND CRAWLING PERFORMANCE FAVORING THE EXPERIMENTAL GROUP WAS ACCEPTED SINCE THE MANN-WHITNEY U TEST COMPARING PRE-POST-TEST GAIN SCORES BETWEEN GROUPS FOUND DIFFERENCES WERE STATISTICALLY SIGNIFICANT AT THE .05 LEVEL. HYPOTHESIS TWO STATING THERE IS A SIGNIFICANT IMPROVEMENT IN PERCEPTUAL-MOTOR PROFICIENCY FAVORING THE EXPERIMENTAL GROUP WAS REJECTED SINCE THE MANN-WHITNEY U TEST COMPARING PRE-POST-TEST GAIN SCORES BETWEEN GROUPS FOUND THE DIFFERENCES WERE NOT STATISTICALLY SIGNIFICANT AT THE .05 LEVEL. HYPOTHESIS THREE STATING THERE IS A SIGNIFICANT MEAN IQ IMPROVEMENT FAVORING THE EXPERIMENTAL GROUP WAS ACCEPTED SINCE AN ANALYSIS OF VARIANCE PRODUCED CORRELATION COEFFICIENTS BETWEEN THE PRE-TEST AND POST-TEST SCORES FOR THE EXPERIMENTAL AND CONTROL GROUPS OF .81 AND .95 RESPECTIVELY AND A DIFFERENCE STATISTICALLY SIGNIFICANT AT THE .05 LEVEL. THE TREATMENT HAD A FACILITATING EFFECT ON BOTH THE PHYSICAL AND INTELLECTUAL DEVELOPMENT OF THE EXPERIMENTAL GROUP. REPLICATION AND LARGER SCALE INVESTIGATIONS ARE NEEDED. APPENDIXES INCLUDE THE CREEPING AND CRAWLING SCALE AND THE KERSHNER-DUSEWICZ-KERSHNER REVISION OF THE VINELAND OSERETSKY TESTS OF MOTOR DEVELOPMENT. BIBLIOGRAPHY LISTS 56 ITEMS. (DF)