In establishing a third legal gender, India’s supreme court this week recognizes a historical view of androgyny first described in Plato’s Symposium as “spherical people” who tried to defy the gods — promising improved rights and quotas similar to other “backwards and disadvantaged” minorities. While still barring homosexuality, the mostly enlightened ruling from the two-judge court grants every Indian a right to “choose their own gender” among three legal sexes.

Now, some research on gender suggests extreme levels of sexual dimorphism — great for sexual reproduction — might lead adolescents toward risky and unhealthy behaviors. Boys and girls who conform most strongly to gender norms are “significantly more likely” than others to engage in carcinogenic behaviors such as smoking and indoor tanning. In a new study from Harvard’s school of public health, the most feminine girls made more frequent use of tanning salons and exercised less than others. Similarly, the most masculine boys smoked and chewed tobacco more than betas and omegas among them in the dominance hierarchy of the American high school.

Published in the Journal of Adolescent Health on Wednesday, the study is the first to examine cancer risk behaviors based on what lead researcher Andrea Roberts refers to as gender expression. "Our findings indicate that socially constructed ideas of masculinity and femininity heavily influence teens' behaviors and put them at increased risk for cancer,” she said in a university news release. “Though there is nothing inherently masculine about chewing tobacco, or inherently feminine about using a tanning booth, these industries have convinced some teens that these behaviors are a way to express their masculinity or femininity.”

Roberts and her colleagues at the university’s school of public health say teenagers engage in risky behaviors that include a heightened long-term predisposition to cancer. But after analyzing data on nearly 10,000 adolescents, they found divergent patterns among those who rated themselves most masculine and most feminine. Among findings, the most masculine boys were nearly 80 percent more likely to chew tobacco and 55 percent more likely to smoke cigars than others who’d rated themselves as less masculine. Likewise, the most feminine girls were 32 percent more likely to visit tanning salons and 16 percent less likely than others to exercise regularly.

Yet the least masculine or feminine kids were more likely to smoke cigarettes, which complicates things. Such adolescents may be smoking in response to social stressors, Roberts said, including social exclusion or harassment related to “gender nonconformity” or perceived sexual orientation.

In either case among the boys, the alphas and omegas were both smoking tobacco — with different definitions perhaps of “cool.” Among the girls, media consumption was found to account for one-third to nearly one-half of the higher likelihood to use tanning salons, with gender conformity explaining most of the difference, according to senior study author S. Bryn Austin.

"Engaging in risk behaviors in adolescence likely increases the risk of engaging in similar behaviors in adulthood," he said in the release. "So it is important to focus on prevention during the teen years, challenging notions such as 'tanning makes one beautiful' or 'cigar smoking and chewing tobacco is rugged or manly.'"

How social marketers approach that challenge is a different matter altogether.

Source: Roberts A, Rosario M, Calzo JP, Corliss HL, Frazier L, Bryn Austin S. Masculine boys, feminine girls and cancer risk behaviors: An 11-year longitudinal study. Journal of Adolescent Health. 2014.