PATTERNS OF THE LINGUISTIC DEVELOPMENT OF CHILDREN OF DIFFERENT SOCIOECONOMIC ENVIRONMENTS WERE DETERMINED BY A STUDY OF WORD ASSOCIATIONS. THE RELATION OF RESIDENTIAL AREA, SOCIAL CLASS, OR SUBCULTURAL GROUP MEMBERSHIP TO LINGUISTIC DEVELOPMENT WAS THE MAIN CONCERN OF THE STUDY. EACH MEMBERSHIP GROUP WAS FURTHER CATEGORIZED ACCORDING TO IQ LEVEL, SEX, AND GRADE. GROUPS WERE COMPARED BY HOLDING CONSTANT AGE AND IQ. THE WORD ASSOCIATIONS WERE OBTAINED IN RESPONSE TO A LIST OF 96 STIMULUS WORDS. EACH CHILD WAS INTERVIEWED ALONE, AND WAS ASKED TO RESPOND WITH THE FIRST WORD THOUGHT OF AS THE INTERVIEWER SAID A WORD ALOUD. RESULTS OF THE STUDY SUPPORT THE FOLLOWING CONCLUSIONS--(1) THERE ARE NEGLIGIBLE DIFFERENCES BETWEEN SURBURBAN CHILDREN FROM UPPER MIDDLE CLASS AND BLUE COLLAR NEIGHBORHOODS, (2) RURAL MARYLAND CHILDREN TEND TO DEVELOP MORE SLOWLY THAN THE SUBURBAN CHILDREN, ESPECIALLY THOSE WHOSE IQ IS AVERAGE OR BELOW, (3) AMISH CHILDREN DEVELOP EVEN MORE SLOWLY THAN THE RURAL MARYLAND CHILDREN, AND (4) WHITE SLUM CHILDREN ARE ADVANCED COMPARED TO SUBURBAN CHILDREN AT FIRST GRADE, BUT RETARDED AT THIRD GRADE. NEGRO SLUM CHILDREN ARE GENERALLY BEHIND WHITE SLUM CHILDREN, BUT AT FIRST GRADE THE NEGRO SLUM CHILDREN ARE ON A PAR WITH WHITE SUBURBAN CHILDREN. RELATED REPORTS ARE AA 000 046 AND AA 000 048. (AL)