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4 Ways That Sexuality Can Be Fluid

New research explores four types of sexual fluidity in women.

Lisa Diamond, famous for her decades-long research on sexual minority women, has published a new paper in Archives of Sexual Behavior outlining four different types of sexual fluidity. Sexual fluidity, discussed in detail in Diamond’s book, Sexual Fluidity: Understanding Women's Love and Desire, is commonly understood as an individual’s capacity for fluctuation in their sexual response as a result of different situations or interpersonal and contextual experiences. To date, researchers have most often explored this concept with respect to sexual orientation and the gender to which individuals are sexually and romantically attracted. One big debate, however, has been whether or not sexual fluidity is distinct from bisexuality, or the capacity to be sexually attracted to more than just one gender.

Within the literature on sexual fluidity, a variety of experiences have been explored, including sexual behaviour that differs from one’s stated sexual identity, changes in attraction or behaviour over the lifespan, or specific situational contexts associated with sexual behaviour/attraction that differs from a previously stated sexual identity. In Diamond’s latest article, she questions whether all of these examples are part of one overarching concept — sexual fluidity — or whether they may be better conceived of as separate constructs or sub-types of sexual fluidity.

In an elaborate study of 76 women, ages 19-37, participants completed an extensive survey about their sexual attractions, identities, and experiences over the previous 12 months, and participated in an in-lab arousal inducing experience, and a two-week daily diary study. Roughly one third (32%) of the participants identified as heterosexual, 42% as bisexual, and 26% as lesbian. During the in-lab arousal induction process, participants listened to eight different stories, of which half were sexual in nature. Some of the stories focused on an interaction with a man while others focused on an interaction with a woman. The participants then rated their degree of sexual arousal to each of the stories in real-time as they listened. During the two-week daily diary study, participants answered questions each night about their experiences of sexual arousal, thoughts about sex, and sexual fantasies, and the degree to which all of these involved men and/or women.

Diamond and her colleagues analyzed the data from these three elements of their study to identify four distinct types of sexual fluidity, with only two showing a slight overlap with each other. In other words, being sexually fluid in one way did not predict being sexually fluid in another, supporting the notion that what researchers have been studying as an ‘overarching’ concept of sexual fluidity may indeed be more nuanced than previously thought.

4 Types of Sexual Fluidity

Situational Fluidity. Situational Fluidity most closely resembles the original theory of sexual fluidity by referring to increased sexual responsiveness across different situational contexts. In the current study, women with greater situational fluidity were also more likely to report becoming sexually active at a younger age and having a greater number of lifetime sexual partners. Diamond explained this by noting that heightened “responsiveness to situation-specific opportunities for sexual contact … [may] amplify [a woman’s] opportunities for sexual contact, thereby increasing their total number of sexual partners and accelerating their initial transition into sexual activity.”

Attraction vs. Behaviour. Fluidity of this nature was marked by sexual attractions that differed from sexual behavior and was measured by comparing the degree to which women reported pursuing sexual experiences with men vs. women compared to their self-reported degree of attraction to men vs. women. Thus, someone who reported being primarily attracted to men but who pursued more experiences with women than with men, or vice versa, would be considered sexually fluid within this category.

Temporal Instability. This type of fluidity, grounded in Diamond’s previous work on dynamical systems theory applied to sexual attractions, assesses the extent to which an individual’s attractions remain stable over time. In this case, the study explored stability over the two-week time period in which the daily diary data was collected.

Responsiveness to Less-Preferred Gender (AKA Bisexuality). One way that an individual can be conceived to be sexually fluid is by showing a capacity for sexual experiences with the gender to whom they are generally less attracted. If that sounds a bit like bisexuality, you’re not wrong, as this type of fluidity may be better construed as bisexuality – or the capacity for erotic responsiveness to partners of different genders without a clear preference in one direction or another. Of the four types of fluidity assessed in the study, this was the only type that was associated with having a bisexual identity.

How do the different types of fluidity relate to each other?

The two types of fluidity that overlapped were the last two — temporal instability and responsiveness to the less-preferred gender. This makes sense, as an individual who might have greater readiness or capacity for attraction to their “less preferred gender” will likely also show greater variability in their attractions and behaviour over time (i.e., temporal instability) due to their attractions being less “anchored” to one particular gender. None of the other types of sexual fluidity were associated with each other at all. For example, having greater responsiveness to one's less preferred gender was not associated with greater situational variability or vice versa.

The study also assessed how the different types of sexual fluidity may be associated with other elements of a woman's sexuality, namely her sex drive and sociosexuality (degree of interest/openness to 'unrestricted' sexuality, such as sex outside of a committed relationship). Interestingly, none of the types of sexual fluidity were associated with women’s reported sex drive or sociosexuality, somewhat contradicting past research.

The articulation of four types of sexual fluidity helps to clarify the conflation of sexual fluidity and bisexuality, while also providing the nuance necessary to allow future researchers to assess the different types of sexual fluidity. One pressing question will be the continued investigation of whether sexual fluidity exists more in women than men. Diamond has previously found evidence of sexual fluidity in men and boys, and suggests that the better question going forward may be whether certain types of sexual fluidity are more common among men vs. women.


Diamond, L.M., Alley, J., Dickenson, J., & Blair, K.L. (2019). Who Counts as Sexually Fluid? Comparing Four Different Types of Sexual Fluidity in Women. Archives of Sexual Behavior. Online First doi:10.1007/s10508-019-01565-1

Diamond, L. M. (2008). Sexual fluidity: Understanding Women's Love and Desire. Harvard University Press.

Diamond, L. M., Dickenson, J. A., & Blair, K. L. (2017). Stability of sexual attractions across different time scales: The roles of bisexuality and gender. Archives of Sexual Behavior,46, 193–204.

Diamond, L. M. (2007). A dynamical systems approach to the development and expression of female same-sex sexuality. Perspectives on Psychological Science, 2(2), 142-161.

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