More people today are sexually active before marriage than ever before. The true reasons are practical and have little to do with changing belief systems.
In America a century ago, only a small minority of women were sexually active before marriage (about 11 percent) (1), compared to a large majority today. The same pattern is observed in other developed countries.
Why are women in developed countries more sexually active before marriage? A long list of practical explanations cut across all belief systems:
The key event here was the widespread adoption of the contraceptive pill in the early 1970s. Because this was highly effective and female-controlled, it took away most of the anxiety about unwanted pregnancy.
Reduced Parental Supervision
Teens are less supervised after school if both parents work full-time and may take advantage of this opportunity for sexual activity. Increased enrollment in higher education means that a lot of young women live apart from their families in an environment that encourages sexual expression. This is in marked contrast to sexually restrictive societies, where young, single women are heavily chaperoned by relatives.
Earlier Sexual Maturation of Women and Later Age of Marriage
In the 1860s, women did not mature reproductively until the age of 16 years, compared to 11-12 years today (2). First marriages are later today also, with European women postponing matrimony until the age of about 29. So there is a very long interval of about 10-20 years between puberty and marriage during which complete sexual abstinence is unlikely.
More Women in the Workforce
As more women enter paid employment and careers, they spend more time preparing for the workforce through third-level education. So the number of single, never-married young women is on the rise. Most of these women are sexually active.
More Gender Equality in Jobs
Women used to be far more economically dependent on fathers and husbands. With greater economic independence and more female-headed households, women are freer to control their sex lives, as feminist writers like Helen Gurley Brown (3) pointed out. This means more premarital sex and increased single parenthood.
Women Are More Competitive and Sensation-Seeking
Contemporary women are more competitive in a number of arenas, from sports to education, politics, and careers. Competitiveness is associated with a hormone profile of high sex drive in both sexes (4). Women's risk profile is converging with that of men, as illustrated by rises in problem drinking and dangerous driving. They are also less risk-averse in sexual matters, increasing premarital sexuality.
About a fifth of American women never marry (5). Of those who do marry, the chances of remaining married to the same person for life are low. The time spent in marriages is decreased by divorce, even if most divorcees remarry. In the U.S., close to half of first marriages end in divorce, and the typical duration of a first marriage is only seven years. Between non-marriage, late marriage, and frequent divorces, larger numbers of women live as singles than ever before, boosting premarital sex.
The Mate Market
A large number of sexually active, single women means that men do not need to marry to enjoy an active sex life. If a man may sleep with various attractive women without any long-term commitment, he is less likely to propose marriage to any of them. So romantic relationships are negotiated on the basis of what typical men want, which is sex early in a relationship with little in the way of a permanent commitment such as marriage. (Note the irony that with “sexual liberation,” women actually lost power in relationships at the same time that they gained power in the economy.)
In a recently-published paper, I tested out some of these ideas in a comparison of 40 countries (6). My analysis looked at acceptance of premarital sex (that is almost perfectly correlated with self-reported sexual behavior).
I found that premarital sex increases in more developed countries that have higher-paid labor force participation by women. Premarital sex increases in countries having weak marriages (i. e., low marriage rates, and high divorce rates). Countries where more children are born outside of marriage are more accepting of premarital sexuality, but very religious countries strongly reject it.
Some of these, such as Pakistan, have severe penalties for premarital sex, up to and including so-called honor killings. In such cases, the impact of religion on sexual behavior is likely more practical than doctrinal. If so, it fits the pattern of sexual behavior adapting to local costs and benefits.
1 Caplow, T., Hicks, L., & Wattenberg, B. J. (2001). The first measured century: An illustrated guide to trends in America, 1900-2000. La Vergne: TX: AEI Press.
2 Daly, M., and Wilson, M. (1983). Sex, evolution, and behavior. Belmont, CA: Wadsworth.
3 Gurley Brown, H. (1962). Sex and the single girl. New York: Bernard Geis.
4 Cashdan, E. (2008). Waist-to-hip ratios across cultures: Trade-offs between androgen- and estrogen-dependent traits. Current Anthropology, 49, 1099-1107.
5 Klinenberg, E. (2012). Going solo: The extraordinary rise and surprising appeal of living alone. New York: Penguin.
6 Barber, N. (2017 b). Cross-national variation in attitudes to premarital sex: Economic development, disease risk, and marriage strength. Cross-Cultural Research, 1-15. DOI: 10.1177/1069397117718143