The study has surveyed approximately 15,000 US twelfth graders each year since the 1976. Summarizing the trends in this data, Stevenson and Wolfers find that “young men have become increasingly happy, while young women have become slightly less happy. While these absolute declines are not as large as those seen among US adults, the difference between these trends implies a large decline in girls happiness relative to that of boy—a difference somewhat larger than that seen among US adults.” (pp. 203-204)
They also observe that, “[s]imilar surveys of eight and tenth graders have also been run since 1991, but interestingly, for those age groups, we find boys and girls both getting happier at roughly equal rates (while for twelfth graders, even over this sub-period, we find girls getting less happy relative to boys).” (p. 204)
So what happens between tenth and twelfth grade that makes boys happier and girls less happy?
Summarizing the data in the , tells us that “On average, young people have sex for the first time at about age 17…” (“Facts on American Teens’ Sexual and Reproductive Health”) Age 17 would be about eleventh grade.
An earlier post on this blog also shows that more than 20% of girls between 14 and 19 have HPV. Trends in both the age of first intercourse and STDs may help explain Stevenson and Wolfers’ intriguing result.
Stevenson, Betsy, and Justin Wolfers, “The Paradox of Declining Female Happiness,, 2009.
The Guttmacher Institute, “Facts on American Teens’ Sexual and Reproductive Health.” Available at: . Accessed 7/2/2012.