RESEARCH ON THE DEVELOPMENTAL ORIGINS OF THE CHARACTERISTICS OF DISADVANTAGED CHILDREN IS NOT AS IMPORTANT FOR SCHOOL PEOPLE AS IS SCHOOL-BASED RESEARCH. SUCH STUDIES FOCUS ON A TASK ANALYSIS APPROACH WHICH WOULD MATCH THE CHARACTERISTICS OF A STUDENTS BEHAVIOR WITH INSTRUCTIONAL PROCEDURES. ONE SPECIFIC PIECE OF RESEARCH STUDIED THE EFFECTS OF SOCIAL CLASS AND ETHNIC GROUP INFLUENCES ON THE DEVELOPMENT OF LEVELS AND PATTERNS OF MENTAL ABILITY BY OBTAINING THE SCORES FOR VERBAL ABILITY, REASONING, NUMBER FACILITY, AND SPACE CONCEPTUALIZATION OF MIDDLE- AND LOWER-CLASS CHINESE, JEWISH, NEGRO, AND PUERTO RICAN FIRST GRADERS. THE EFFECTS OF ETHNICITY UPON THE MENTAL PATTERNS WERE THE MOST STRIKING FINDINGS, FOR THE PATTERNS WERE CLEARLY DIFFERENT AMONG ETHNIC GROUPS. WITHIN ETHNIC GROUPS SOCIAL CLASS DIFFERENCES AFFECTED ONLY LEVEL AND LEFT PATTERN UNCHANGED. SOCIAL CLASS WAS A MORE INFLUENTIAL FACTOR IN THE LEVEL OF ABILITY OF NEGROES THAN AMONG ANY OTHER GROUP. THESE FINDINGS SUGGEST FURTHER STUDIES OF (1) DIFFERENTIAL ETHNIC GROUP PATTERNS AS PREDICTORS OF ACHIEVEMENT, (2) THE STABILITY OF THESE PATTERNS, (3) THEIR DEVELOPMENTAL ANTECEDENTS, AND (4) APPROPRIATE TEACHING STRATEGIES. IN CONTRAST TO THE COLEMAN REPORT'S STRESS ON EQUAL EDUCATION TO PRODUCE EQUAL ACHIEVEMENT LEVELS AMONG ALL GROUPS, THE FINDINGS OF THIS STUDY SUGGEST THAT EMPHASIS ON EQUAL OPPORTUNITIES FOR EQUAL AND MAXIMUM DEVELOPMENT OF GROUPS WOULD BE MORE SUCCESSFUL POLICY. (NH)