We hear a lot about the Big Three Sexualities — straight, bisexual and gay. Most of us assume that these three orientations encompass the universe of sexual identities. But there is a new kid on the block: The mostly straight male. Ritch C. Savin-Williams, author of Mostly Straight: Sexual Fluidity Among Men

The followup sentence in developmental psychologist Ritch C. Savin-Williams‘s new book (excerpt available at Time):

To the uninitiated, mostly straight may seem paradoxical. How can a man be mostly heterosexual? If you’re a young man, you might assume that either you’re straight or you’re not, meaning you’re likely gay and maybe bisexual. Yet the evidence suggests that more young men identify or describe themselves as mostly straight than identify as either bisexual or gay combined.

Key to this revelation is a social climate in which a researcher can ask the right question, and some men can feel open enough to admit their truth. “However,” writes Katherine Heaney, Cornell Daily Sun, “when Savin-Williams asked these young men if they have told people that they are ‘mostly straight,’ most of them said no.”

“This is far less of a matter of embarrassment, Savin-Williams said, but mainly because it is not a recognized term so they do not think people would understand what they mean.”

The author’s research involved 40 young men, mostly students at Cornell where he teaches, who described themselves as mostly straight. Additional description of what this means:

The mostly straight man belongs to a growing trend of young men who are secure in their heterosexuality yet remain aware of their potential to experience far more. Perhaps he’s felt attracted to or fantasized about another guy to a slight degree or intermittently. He might or might not be comfortable with this seeming contradiction, a hetero guy who, despite his lust for women, rejects a straight label, a sexual category and a sexual description that feels foreign. He’d rather find another place on the sexual/romantic continuum, some location that fits him more comfortably.

In a recent article in The Cut, Savin-Williams identifies his major findings, summarized by me below:

• About 5 to 10 percent of males will use the mostly straight label if given a choice to do so.
• These men aren’t “closet cases,” i.e., they are not gay.
• They are more open to the possibility of a gay attraction than men who see themselves as straight, but it doesn’t mean they lean heavily in that direction.
• In the lab mostly straight men exhibited physiological evidence of attractions to men.

Notably, a comparable 2008 book regarding women’s sexuality, written by psychology professor and researcher Lisa M. Diamond, PhD, has also been covered on this blog (see “Sexual Fluidity” by Lisa Diamond: New Thoughts About Identity) and was actually reviewed by Savin-Williams.

About Diamond’s Sexual Fluidity: Understanding Women’s Love and Desire: “Probably the most surprising finding of the study was how often women changed the way that they thought about their sexual identity over time,” she told Big Think. Rather than stability of identity, the norm was changeability of identity, often back and forth.