In a longitudinal study, the substance use/abuse histories were obtained on a community sample of 640, (mean age of 24.9 years) randomly selected from the 8,000 Philadelphia black subjects who had been studied comprehensively from birth to seven years of age in the National Collaborative Perinatal Project (NCPP). Among other conclusions, it is postulated from some of the many significant associations found between early life variables and substance use/abuse in early adulthood, that an infant is at risk who has the following combination of characteristics and family situation: outgoing, responsive, assertive or impulsive, or willful, and who is in an unfavorable family environment, with a mother who is generally negative toward the infant, has a larger number of small children and has had more fetal deaths, in a generally poor social environment.