SALT LAKE CITY—Bisexuality is not a phase or avoidance of coming out as gay, a researcher has found, but a distinct sexual orientation that remains constant over time.

That’s the conclusion of University of Utah psychology professor Lisa Diamond, who followed 79 non-heterosexual women over a 10-year period. Diamond’s results were published in this month’s issue of Developmental Psychology.

“We’re a culture that still has a very rigid notion of sexual categories: If you’re not totally gay you must be totally straight,” Dr. Diamond said. “Bisexuality throws that right out the window. So it’s easier to dismiss bisexuality as not being real.”

Of the women in the study who identified as bisexual in 1995, 92 percent still did so in 2005, Diamond said.

Diamond also said more research is needed on bisexuality, noting that people who identify as bisexual are often excluded from research groups on sexual orientation because researchers don’t want to deal with the implications of including them.