title: Gender and ethnic differences in the timing of first sexual intercourse.
abstract: BACKGROUND
  Whether the effect of gender on the risk of first intercourse in influenced by adolescents ethnicity has received limited attention in research on age at first sex. Such information could provide a more complete understanding of adolescent sexual behavior.
  
  
  METHODS
  Life-table analysis using data from a population-based, ethnically diverse sample of 87/Los Angeles County youths was employed to estimate the median age at first sex for each gender-and-ethnicity group. Multivariate analysis using proportional hazards techniques was conducted to determine the relative risk of sexual activity among teenagers in each group.
  
  
  RESULTS
  Overall, the teenagers in the sample had a median age at first sex of 16.9 years. Black males had the lowest observed median (15.0), and Asian American males the highest (18.1); white and Hispanic males, and white and black females, reported similar ages (about 16.5 years). Hispanic and Asian American females had rates of first sex about half that of white females, although these protective effects were explained by differences in family structure. Even after controlling for background characteristics, black males had rates of first sex that were about 3-5 times the rates of the other gender-and-ethnicity groups. In addition, Asian American males were less likely than Hispanic males to be sexually experienced, and Hispanic males had almost twice the rates of sexual activity of Hispanic females.
  
  
  CONCLUSIONS
  Socioeconomic conditions account for ethnic differences among females in the age at first sex, and cultural influences may contribute to the difference between Hispanic males and females; explanations for black males, however, remain elusive.
authors.affiliation: University of California, Los Angeles, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Upchurch
authors.forename: L
authors.initials: L
authors.lastname: Levy-Storms
authors.forename: C A
authors.initials: CA
authors.lastname: Sucoff
authors.forename: C S
authors.initials: CS
authors.lastname: Aneshensel
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology*; D001741:Black or African American / Q000706:statistics & numerical data; D000367:Age Factors; D001213:Asian; D003075:Coitus; D005190:Family; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D015993:Life Tables; D015141:Los Angeles; D008297:Male; D016016:Proportional Hazards Models; D012737:Sex Factors; D012725:Sexual Behavior / Q000208:ethnology*; D012959:Socioeconomic Factors; D044465:White People / Q000706:statistics & numerical data