Sexual Fluidity: Understanding Women's Love and Desire . LISA M. DIAMOND . Cambridge , MA : Harvard University Press , 2009 . 352 pp., $17.95 (paperback) ISBN: 9780674032262 .

Lisa Diamond wants to spark a revolution in how we think about women's experiences of sexual desire. In her own research with a group of women she has been following since 1995, she has found that the standard model of sexual orientations—three categories, stable and innate—do not hold true for many of her participants. In Sexual Fluidity, she seeks to explain her findings by bringing together research from a variety of theorists, researchers, and disciplines to create a cohesive model of women's sexual attractions.

She carefully presents her argument in each chapter. The book begins with a review of the early literature on sexual fluidity that sought to explain women's often-unexpected transitions from attractions to men to attractions to women (or a specific woman). Recognizing that this pattern is different from bisexuality and does not necessarily fit into the mold of innateness or social constructionism, Diamond sought to understand women's experiences fully, not simply as aberrant noise in the data. In achieving these goals, Diamond integrates the experiences of her participants, two-thirds of whom changed their sexual self-identification at least one time across the 10 years of her study.

Many feminists have been critical of biological explanations for women's behavior because these explanations have often perpetuated a deficit model of women's sexuality. In regards to current biological assumptions about sexual desire, Diamond points out what many of us already know: They do not often fit women's experiences. In this book, Diamond develops her own model of women's erotic potential that explains why biological models of women's sexualities are so inconsistent. She posits that women's biology sets a range for their sexuality, which can interact with their environmental experiences throughout the life span. Diamond's model can be used to explain why some women “come out” late in life (having experienced no previous desire for female partners) as well as why lesbians become attracted to men (much to their own surprise).

Diamond takes the perspective that “sexual feelings and experiences are embedded in both physiological-biological and sociocultural strategies” (p. 22). She suggests that romantic love for women can develop in the absence—and independently—of sexual desire, and for many women, romantic love can lead to sexual desires. She also suggests that romantic love does not have an “orientation,” unlike sexuality. Diamond argues that the amount of variation in a woman's sexual desire is based on her degree of dispositional fluidity (i.e., a biological set point) as well as her exposure to social and environmental factors.

This book is a must read for anyone who is interested in sexual attraction. The author challenges us, indeed requires us, to rethink our notions of identity and sexual categories. Lisa Diamond writes that “instead of asking ‘What makes some women lesbians?’ we need to ask ‘What factors create both stability and change in women's same sex and other-sex sexuality?’”(p. 241). She also suggests that, when we are asked whether homosexuality is genetic or environmental, we should respond, “What kind?” Diamond does not claim to have all the answers (although this book is her attempt to explain as much as she can), but rather she is one of the first to ask the right questions about women's sexual desire. Lisa Diamond presents radical and refreshing ideas, and it is about time.

Christine Smith, Ph.D., is an assistant professor of psychology and human development at the University of Wisconsin–Green Bay.