The Kinsey Scale Today
In the middle of the 20th century, a man obsessed with flowers and 78 rpm records intervened so significantly in the field of sexology that his work, while now seen by some people as outmoded, still garners interest today.
Destigmatizing sexual behaviors
The biologist-turned-celebrity Alfred Kinsey, Sc.D., founded the Institute for Sex Research, later renamed the Kinsey Institute, in 1947 at Indiana University. A year later, he and the institute published "Sexual Behavior in the Human Male," followed by "Sexual Behavior in the Human Female" in 1953. Those reports helped change the public perception of sexuality and sold 1 million copies combined.
Kinsey's 1948 report featured the Heterosexual-Homosexual Rating Scale—known as "the Kinsey Scale"—based on interviews with thousands of people about their sexual histories, data that was collected as meticulously as Kinsey collected flowers (irises, in particular). His 0 to 6 scale documented sexual behaviors along a heterosexual-homosexual continuum, with a seventh "X" option reserved for people with no sexual contacts or reactions.
The scale was derived, in part, from Katharine Bement Davis' scale detailed in the 1929 text, "Factors in the Sex Life of Twenty-Two Hundred Women," and first outlined by Kinsey around 1940. His new 1948 report aimed "to eradicate sexual identity categories altogether in order to eliminate sexual identity-based persecutions and to promote equal rights," wrote sexuality historian Donna Drucker in a 2010 article published in the Journal of Homosexuality.
"As proponents and opponents of homosexual rights both depended on constructions of sexual identity to advance their agendas, Kinsey's ideal was never realized," she wrote.
With the new scale, Kinsey based human sexuality primarily on behavior rather than identity and aimed to destigmatize sexual behaviors while getting beyond a heterosexual-homosexual binary.
"Males do not represent two discrete populations, heterosexual and homosexual," he wrote in his seminal study. "The world is not to be divided into sheep and goats…The living world is a continuum in each and every one of its aspects. The sooner we learn this concerning human sexual behavior, the sooner we shall reach a sound understanding of the realities of sex."
That was about 75 years ago. Today, Kinsey's insights and scale receive both criticism and praise.
Criticisms of the Kinsey Scale
In an article published in 2020 by Proceedings of the National Academy of Sciences (PNAS), Brendan Zietsch and Morgan Sidari took the Kinsey Scale to task for conflating two different constructs. This construction, they argued, placed the degree of sexual behavior with opposite-sex people and same-sex people in opposition to arrive at a singular score.
The authors argued against the validity of that approach. Contrary to the assumption upon which Kinsey designed his scale, they contended there's no evidence-based inverse relationship between same-sex and opposite-sex sexual behaviors and no solid evidence for placing those behaviors on opposite ends of one continuum.
"The structure of the underlying phenomenon is that there are two distinct dimensions: attraction to same-sex and attraction to the opposite sex," explained Brendan Zietsch, Ph.D., associate professor in the school of psychology at the University of Queensland in Brisbane, Australia, in an email. "Some questions regarding biological and environmental influences could be answered using the Kinsey Scale, but the answers might be misleading, and some questions couldn't be answered with it at all."
According to Pablo Mangas, a researcher with the Mind, Brain and Behaviour Research Centre (CIMCYC) at the University of Granada in Spain, the scale neglects "most sexological realities," which is ironic now in retrospect, given the Kinsey quote above about an "understanding of the realities of sex." Mangas agrees with the criticism raised by Zietsch and colleagues, and with other strident assessments of the scale.
"The Kinsey Scale has been labeled as biphobic," Mangas said. "Let me explain: the Kinsey Scale conceptualizes bisexuality as a midpoint between homosexuality and heterosexuality, when, in fact, it is not a midpoint between the two. The Kinsey Scale states that you are more or less bisexual to the extent that you are more or less hetero/homosexual. That's not how it works. I know bisexual activists who fight against it and criticize the scale. Sexual orientation has been wonderfully explained by a continuum for several decades, but now we need some other tool that is also simple and more embracing of diversity."
Current uses and reappraisals
Zietsch doesn't dispute the significance of the Kinsey Scale, however. He called it "groundbreaking," given the effect that the scale and Kinsey's reports had on widespread thinking about sexuality.
"Sexual orientation was seen in a categorical way," Zietsch said about the prevailing view prior to Kinsey's work. "You were either gay or straight. Kinsey introduced the notion that it was more of a continuum, as reflected in his scale.
"Existing data using the Kinsey Scale can still be useful," he added. "But I don't think it should be used in future research."
Zietsch and Sidari used raw genital arousal scores from a study published in 2020, "Robust Evidence for Bisexual Orientation Among Men," to highlight a lack of correlation between genital arousal in response to male stimuli compared to female stimuli.
Jeremy Jabbour and J. Michael Bailey, two of the authors of the paper reporting those results, responded in PNAS with the suggestion that Zietsch and Sidari didn't adjust for factors extraneous to sexual orientation (for example, responsivity), which would call into question conclusions about the correlations or lack thereof they pointed to in their article.
Jabbour and Bailey also anticipated and addressed whether sexual arousal to male stimuli might be negatively correlated with arousal to female sexual stimuli.
"If sexual arousal to men and sexual arousal to women are uncorrelated, then genital arousal to one sex should not provide any information about subjective arousal to the other sex," the authors explained before underscoring a finding based on their research cited above. "For both sexes, however, higher genital arousal to one sex was associated with reduced subjective arousal to the other."
The assumption Kinsey baked into his scale circa 1948 around the dimensions of sexual arousal/behavior might not be wholly off the mark, as Jabbour and Bailey suggested arousal patterns and sexual orientation appear unidimensional, at least in part.
Bailey explained via email that he thinks he and Jabbour refuted the extreme thrust of the Zietsch and Sidari argument, and he affirmed the factual tendency for higher arousal to male stimuli to predict lower arousal to female stimuli.
"I was a skeptic of the need for the Kinsey Scale for a long time, and also of the self-report nature of the scale," Bailey explained. "Self-report is definitely sometimes false, on purpose or not. But our big PNAS study showed that, in fact, some men do have bisexual arousal patterns, which I had doubted until about 10 years ago."
Still important after almost 75 years
Other recent research endeavors deployed the Kinsey Scale, hinting at possible present-day applications, shortcomings notwithstanding. For example, authors of a study published in January 2022 in the International Journal of Environmental Research and Public Health used scores from the Kinsey Scale to separate participants into gay and heterosexual subgroups.
"Although there are alternatives to the Kinsey Scale, because of its brevity and conciseness—as well as because of how widely used it has been in this field of research—we always tend to make use of it," explained Mangas, the study's lead author.
"We find it a reliable tool for differentiating between people's sexual behaviors," he continued, but noted, "Logically, it is not the greatest tool, since it must be kept in mind that the Kinsey Scale assesses sexual behavior, not sexual orientation per se. Sexual orientation is more than purely behavioral, hence, there are probably better alternatives that we will work with in the future."
Mangas listed several advantages the scale still boasts, such as the brevity and simplicity it offers, people's familiarity with the scale, how easy it is to understand, and how easy it is to work with the data it generates. As he confirmed, its use remains widespread, but he did acknowledge that it renders some experiences invisible.
The scale focuses almost exclusively on one component—behavioral—of sexuality. It doesn't account for sexual behavior and desire when they don't correspond, and it fails to engage the full range of sexual diversity.
"Now we know that Kinsey was not very correct in some of his postulates, but his work has been reconceptualized for decades, and we should not deny that it is a very important reference in the field of sexology," Mangas said. "I, personally, have learned a lot from his figure and I have more to thank him for than to blame him."
