TWO COMPREHENSIVE STUDIES OF THE ROOTS OF VIOLENT AND OTHER ANTISOCIAL BEHAVIOR IN CHILDREN AND OF THE ANTISOCIAL PERSONALITY IN ADULTS HAVE BEEN CONDUCTED AT THE WASHINGTON UNIVERSITY SCHOOL OF MEDICINE IN ST. LOUIS. MOST ANTISOCIAL BEHAVIOR WAS CHARACTERIZED BY A LIFETIME OF EXPOSURE TO HARDSHIP, AND WAS FOUND IN THE LOWER ECONOMIC CLASSES. ONSET OF AN ANTISOCIAL PERSONALITY IS EARLY, PARTICULARLY AMONG BOYS. AMONG THE 500 CHILDREN STUDIED AND REFERRED TO A CHILD GUIDANCE CLINIC BECAUSE OF ANTISOCIAL BEHAVIOR, ONE-FOURTH BECAME ANTISOCIAL ADULTS, ONE-TWELFTH WERE ALCOHOLICS OR DRUG ADDICTS, ONE-NINTH WERE PSYCHOTIC, AND ONLY 16 PERCENT RECOVERED BY THE AGE OF 18 AND HAD NO FURTHER PSYCHIATRIC PROBLEMS. NO ONE SYMPTOM MARKED EVERY PERSON WHO BECAME DELINQUENT AS AN ADULT, BUT SOME SYMPTOMS WERE COMMON INCLUDING THEFT, TRUANCY, RUNNING AWAY FROM HOME, AND DISCIPLINE PROBLEMS AT SCHOOL. THE NUMBER OF SYMPTOMS WAS A CONSIDERABLY BETTER PREDICTOR OF FUTURE ADULT CRIMINALITY THAN ANY ONE SYMPTOM OR COMBINATION. SEX, RACE, AND PARENTAL BEHAVIOR WERE FOUND TO INFLUENCE ANTISOCIAL BEHAVIOR. OF THE CHILDREN WHOSE PARENTS EXERTED NO DISCIPLINE BECAUSE OF DISINTEREST, THE RATE OF ANTISOCIAL PERSONALITY AS ADULTS WAS ABOUT 30 PERCENT. PREVENTION OF TRUANCY IN THE FIRST AND SECOND GRADES AND PROHIBITION OF ALCOHOL BEFORE AGE 15 APPEARED TO REDUCE TENDENCIES TOWARD DELINQUENCY. CHILDREN WITH DISTURBED NEUROMUSCULAR DEVELOPMENT ARE MORE LIKELY TO BE IDENTIFIED AS DELINQUENTS WHEN THEY GROW UP IN A LOWER-CLASS CONTEXT AND TO BE IDENTIFIED AS CHILDREN WITH LEARNING DISABILITIES WHEN THEY COME FROM MIDDLE-CLASS ENVIRONMENTS. REFERENCES ARE INCLUDED IN THE BOOKLET. (LWM)