Background and objectives: Arguments for population-based research on patterns of sexual behavior are reviewed, and survey data are used to illustrate the insights that can be gained from such research.
Study design: Reports of sexual behavior obtained in surveys of large probability samples of the U.S. population are analyzed and compared to make inferences about changes in the age of onset of sexual intercourse and the patterns of heterosexual and same-gender sexual behaviors of American men and women who entered adulthood during the period from 1930 to 1990.
Results: Strong trends are documented for both a decline in the reported age at first heterosexual intercourse and an increase in the numbers of heterosexual partners reported during adulthood. Similar evidence on patterns of same-gender contact indicate a relatively stable prevalence of reported male-male contact for cohorts of men born from the 1930s through the 1960s. Preliminary analyses suggest, however, that there has been a substantial increase in the proportion of women reporting female-female sexual contact during adulthood. Although the analyses require refinement, it appears that the prevalence of reported female-female contact may have increased by a factor of 3 to 4 for cohorts of women born between the 1930s and the 1960s.
Conclusions: Although the trends in reported behaviors are robust, inferences about behavior, pre se, rest on the assumption that reporting biases were equivalent across cohorts. Methodological challenges in the interpretation of such findings and new technologies for conducting such research are described.