Sex, Marriage, and Children: Trends Among Millennial Women

Occasionally, I have a conversation with someone who thinks that most young women today are uninterested in marriage and children and wish to pursue having sex with large numbers of partners instead. In this post, I will argue that this narrative is basically false. Women today do not have a large number of sexual partners and they are still getting married and having children. The difference between Millenials and past generations is that they are starting their families slightly later in life, and so having a slightly longer period of serial monogamy.

Sex

With regards to sexual partners, the CDC reports that the average woman between the ages of 25 and 44 reports having had 4.3-lifetime sexual partners. This figure is probably too low because some women will claim to have had fewer sexual partners than they actually have. Young males report having had sex with an average 6.6 women. This figure is probably too high because some men will claim to have had more sexual partners than they actually have. On average, men and women are probably having roughly five lifetime sexual partners.

The CDC also provides data on the frequency with which women have 15 or more lifetime sexual partners. Such behavior is rare: only 10.8% of women under the age of 44 reported having such a high number of sexual partners.

These numbers vary by race, and many of the people who are concerned about the behavior of millennial women are also concerned about the changing demographics of America. Because of this, it is worth noting that data from the general social survey shows White women report having had an average of three sexual partners while White men report an average of five. By the same logic as before, White men and women have probably had an average of four-lifetime sexual partners.

Some might argue that four to five lifetime sexual partners is higher than ideal. Even if that is true, this figure obviously indicates a pattern of serial monogamy, not sleeping around. The average age of first marriage is 27, meaning that women could easily fit in four to five relationships, lasting one or more years each,  in-between the time that they start to date and the time that they get married.

The previously referenced analysis of GSS data also broke the numbers down by year. This data suggests little change in the last two and a half decades:

The CDC’s analysis also displayed data for multiple years. It shows an increase of 0.5 average male sexual partners for US women in general between the years 2001 and 2013.

Another analysis of GSS data which combined races and sexes found that lifetime sexual partners rose through most of the 20th century but turned around with people born after the 1970s. Millenials reported having no more partners that did people born in the late 1940s.

Thus, most millennial women are not having a large number of sexual partners, and there is no trend of women becoming more sexually promiscuous over the last few decades.

Marriage

With respect to marriage, most women are still getting married, but they are doing so three to four years later than in the past.

These trends are somewhat misleading due to the rise in non-marital cohabitation. According to Pew, 9.2% of millennials are currently cohabitating with a significant other compared to just 5.2 % of generation Xers who were cohabitating in 1998. Rates of cohabitation in earlier generations were presumably even lower. Adjusting for these differences would eliminate a significant fraction of the cohort disparities in the proportion of people who never marry seen above.

That being said, the age at which people marry is definitely increasing. The median age at which women marry has changed from 23.5 in 1890 to 20.5 in 1950 and 27 in 2010. The median age at which men marry has been more stable, moving from 26.5 in 1890 to 24 in 1950 and up to 28.5 in 2010.

Among those who have not yet married, the desire for marriage is still very strong. According to Gallup, 86% of millennials who are not already married want to be someday.

Children

Also according to Gallup, most adults under the age of 40 have children, and more than 90% of adults under 40 want children someday. These figures were basically the same in 2013 and 2003.

The overall fertility rate fell during the 1960s and stabilized in the mid-1970s.

Fertility rates have been rising for women between the ages of 30 and 44, stagnant for women between the ages of 25 and 29, and falling for women 24 and younger.

As millennials get older, the number of millennial mothers is quickly rising:

If we look at these trends by race, we see that the White fertility rate has risen since the 1980s while the fertility rate for all other groups has fallen.

It used to be that Whites had the lowest fertility rate of any major racial group. For the last 20 years, Asians and Amerindians have had lower fertility rates than Whites. If current trends continue, the fertility rates of Blacks and Hispanics may fall below those of Whites within the next 20 years.

Extending the analysis back further, the White fertility rate declined from 7.04 in 1800 to 5.42 in 1850, to 3.56 in 1900, and 2.98 in 1950. Thus, the White fertility declined for nearly all of American history but may have bottomed out in the 1980s. Black fertility has also been declining for well over 150 years, but it may very well continue to do so in the coming decades.

Conclusion

To sum up: Millennial women are not having sex with all that many males and are probably engaging in serial monogamy until their late 20s/early 30s, at which point most of them get married and have children. Most young people who are not yet at this stage of life say that they want to get married and have kids in the future, so we can reasonably expect these trends to continue. By and large, millennials seem to still be engaging in family life, they are just doing so a little later than previous generations did.