SCHOOL ENTRANCE VARIABLES AFFECT LATER STUDENT PERFORMANCE. THIS STATEMENT WAS STUDIED BY ANALYZING THE EFFECTS OF CHRONOLOGICAL AGE AND READINESS LEVEL AT SCHOOL ENTRANCE AND SEX AND RACIAL DIFFERENCE (WHITE AND NEGRO) ON THE FOURTH-GRADE ACHIEVEMENT AND PERSONALITY ADJUSTMENT OF 1,110 PUPILS OF 39 SCHOOLS LOCATED IN CULTURALLY DEPRIVED AREAS OF METROPOLITAN NASHVILLE, TENNESSEE. RESULTS OF TESTS ADMINISTERED IN GRADE 4 SHOWED THAT FIRST-GRADE READINESS WAS THE MOST IMPORTANT FACTOR AFFECTING LATER STUDENT ACHIEVEMENT. THIS SUGGESTS THAT A COMMUNITY-WIDE PRESCHOOL DEVELOPMENT TESTING PROGRAM TO RAISE THE READINESS LEVEL OF STUDENTS SHOULD BE CARRIED OUT. THIS PAPER WAS PRESENTED AT THE INTERNATIONAL READING ASSOCIATION CONFERENCE (BOSTON, APRIL 24-27, 1968). A MORE COMPLETE REPORT OF THIS RESEARCH WAS REPORTED IN A DISSERTATION (UNIVERSITY OF TENNESSEE, JUNE 1967) WHICH IS AVAILABLE FROM UNIVERSITY MICROFILMS. (BS)