Researchers in Washington State University’s psychology department found information that argues sexual orientation may be categorical.

Lead author of the study Alyssa Norris, psychology department Chair David Marcus and University of Southern Mississippi’s Bradley Green found data on sexual orientation that challenges the spectrum theory.

Based on the researchers’ article, titled “Homosexuality as a Discrete Class,” published by the Association for Psychological Science, compelling data was found that argues sexual orientation is category based. This conflicts with the idea of sexual orientation falling on a spectrum, which Alfred Kinsey hypothesized based on surveys conducted in the late 1940s and early ‘50s.

“There have been sort of two ways about thinking about many things in our culture, not just our sexual orientation,” Norris said. “Those two ways are to perceive something that is on a spectrum continuum, or seeing something as being categorical, where there are actual meaningful differences between groups of people based on whatever it is you’re looking at.”

What Norris and company discovered was that sexual orientation consists of important groups rather than being on a spectrum.

The individuals surveyed had their sexual identity, behavior and attraction taken into account when evaluating their sexual orientation, Norris said. According to the study, each individual’s response toward the three variables were recorded on a scale of “exclusively same sex” to “exclusively other sex,” with varying levels of attraction, identity and behavior in-between. The results were recorded separately between men and women.

By analyzing the three variables, people either ended up in a heterosexual group or a non-heterosexual group, Norris said. There is validity to both groups, and one’s response patterns involving these three variables are the key.

“Based on the pattern of responding, there are people that report a level of same-sex orientation that is distinct from those people in the heterosexual group,” Norris said.

There are also several biological theories of sexual orientation supported by the research, Norris said. The survey supports current research of heritability, which suggests there are familial roots tied to sexual orientation in both men and women.

“We can’t prove why or how these groups exist; that’s a major point to make,” Norris said.

The study also showcased non-heterosexual groups being at greater risk of certain disorders such as depression, anxiety and alcohol abuse, Norris said. This is in large part due to the decades of negative stigmas reinforced by society against non-heterosexuals.

It is important to note that while the study suggests these categories might exist and supports other biological theories, Norris said this does not disprove the spectrum theory.

“It’s pointing in a certain direction, but it is by no means a definitive ‘here is exactly what’s going on,’” Norris said. “We can’t speak to that based on this study.”

Reporting by Darold Lee Bivens