Lisa M. Diamond is a psychologist and feminist. She is a professor of developmental psychology and health psychology at the University of Utah. Her research focuses on sexual orientation development, sexual identity, and bonding.
She is best known for her 2008 book, Sexual Fluidity: Understanding Women’s Love and Desire. In this book, she discusses the fluidity of female sexuality, based on her study of 100 non-heterosexual women over a period of 10 years. She concluded that the term bisexual did not truly express the versatile nature of many of her subjects. Therefore, she calls “for an expanded understanding of same-sex sexuality”.