IQ, Birth Weight, and Number of Sexual Partners in White, African American, and Mixed Race Adolescents

Mean levels of three characteristics—verbal IQ, number of sexual partners, and birth weight—were examined in African American, White (European-descent) Americans, and Black/White mixed race American adolescents. The sample came from Wave 1 of the National Longitudinal Study of Adolescent Health. The mean age was 16 years. According to their interviewers, the mixed race children had an African American physical appearance. The African American adolescents had a lower birth weight, a lower verbal IQ, and a higher number of sexual partners than did White adolescents. For each characteristic, the mixed race mean fell between the means of the two parental populations. Design extensions were proposed that include: (1) directly genotyping for individual racial admixture, (2) including parents of the mixed race children, and (3) including their cousins.