Prenatal androgen exposure correlates with same-sex sexual behavior in women.[18] Biological characteristics known to be affected by prenatal hormone exposure have been shown to vary by sexual orientation in women.[19][20] The finding that digit ratios (one characteristic affected by prenatal hormone exposure) differ between lesbian and heterosexual women has been replicated in cross-cultural studies.[20] Neuroimaging studies have found differences between heterosexual and homosexual women in neurological structures, including both those known to be affected by prenatal androgen exposure[21] and those not known to be affected by prenatal androgen exposure.[22][23] A later meta-analysis concluded that the small sample sizes and small number of studies meant that findings were inconclusive as of 2021.[24] Genetics plays a role; around 20% of the variance of sexual orientation in women is controlled by genes.[25]

When a woman realizes she is a lesbian, it may cause an "existential crisis". When a woman was raised in an environment with negative stereotypes of lesbians, she may need to work through these stereotypes and prejudices to come to terms with her orientation.[26]: 93  Lesbians in modern times share an identity that parallels those built on ethnicity, including the concept of group heritage and group pride.[27] Compared to gay men, lesbians more often developed their sexual self-concepts either alone or in intimate relationships, instead of in communities, and disclosed them less often.[26]: 153 

Some women report a consistently lesbian orientation. Other women report varying degrees of fluidity in how they describe their sexual orientation.[28] Women who identify as lesbians and report never having been with men may be referred to as "gold star lesbians." Women who identify as lesbians and had sex with men before coming out may face ridicule from other lesbians or identity challenges with regard to defining what it means to be a lesbian.[29]

Several studies have found that the sexual behavior and attractions of exclusively lesbian women are significantly more likely to be aligned with their identity than those of exclusively heterosexual women. These included studies of reported attraction throughout the fertility cycle, and direct measures of arousal by different imagery.[30]

Some lesbians also identify as non-binary or queer.[31][32][33] Other lesbians find the term "queer" overly broad, inaccurate, or radically politically charged, or associate the word primarily with its use as a slur.[34][35][36][37]

Some researchers observe that self-applied identity labels and reported sexual behavior do not always align: for example, some self-identified straight women report sex with women, and some self-identified lesbians report sex with men.[5]: 22 [38] Some women use the self-identifier "bisexual lesbian" when they are attracted to both sexes, but primarily to women.[39]

A 1983 survey asked couples "About how often during the last year have you and your partner had sex relations?". The survey found that long-term lesbian couples named lower numbers than long-term heterosexual or homosexual male couples.[40] This conclusion became known as "lesbian bed death".[41] Numerous critiques were leveled at the study, including that the language could be misinterpreted to mean "heterosexual intercourse", and that the survey sample was limited to a biased sample of self-identified lesbians in 1983.[42]

Researchers report that lesbian and heterosexual women are just as likely to view achieving orgasm as important,[43] and that the two groups report statistically equivalent rates of overall sexual and romantic satisfaction.[44][45] The research suggests that lesbian women tend to achieve said satisfaction through higher quality rather than more frequent sex, and that they engage in different romantic and sexual scripts than heterosexual women.[45][43]

The most extensive early study of female homosexuality was the 1953 Kinsey Institute analysis of the sexual experiences of more than 8,000 American women. Its methodology has been criticized,[70][71][72] but it proved popular. It reported that 28% of women had been aroused by a female, that 19% had had sexual contact with a female,[73]: 453  and that some 9% had orgasmed.[73]: 453–454  Its dispassionate discussion of homosexuality as a form of sexual behavior was revolutionary.[72]

In 1976, sexologist Shere Hite did a qualitative survey of 3,019 women on their sexual experiences. Hite's questions focused on how women identified and what they preferred, rather than their prior experiences. Respondents indicated that 8% preferred sex with women, while 9% said that they identified as bisexual or had had sexual experiences with men and women without indicating a preference.[74]

A systematic review conducted in 2023 found that lesbian and bisexual women were 1.5 to 2 times more likely to have asthma than heterosexual women. Additionally, they were somewhat more likely to experience back pain, hepatitis B/C, and urinary tract infections. However, they were less likely to suffer from heart attacks, diabetes, or hypertension, possibly because they avoided pregnancy in the case of the latter two conditions.[86] Due to lifestyle and social factors, lesbians may be at elevated risk of some types of cancers.[87]

American studies in the 2010s and 2020s have found that LGBT people experience higher rates of mental distress, and that this relationship is mediated by experiences of rejection and adverse childhood experiences.[88]