Bisexuality does not require that a person be attracted equally to both sexes; one may still have a distinct preference for one sex over the other while identifying as bisexual. A 2005 study by researchers Gerulf Rieger, Meredith L. Chivers, and J. Michael Bailey,[8] which attracted media attention, purported to find that bisexuality is extremely rare in men. This was based on results of controversial penile plethysmograph testing when viewing pornographic material involving only men and pornography involving only women. Critics state that this study works from the assumption that a person is only truly bisexual if he or she exhibits virtually equal arousal responses to both opposite-sex and same-sex stimuli, and have consequently dismissed the self-identification of people whose arousal patterns showed even a mild preference for one sex. Some researchers say that the technique used in the study to measure genital arousal is too crude to capture the richness (erotic sensations, affection, admiration) that constitutes sexual attraction.[9] The National Gay and Lesbian Task Force called the study and The New York Times coverage of it flawed and biphobic.[10] FAIR also criticised the study.[11]
In 1995, Harvard Shakespeare professor Marjorie Garber made the academic case for bisexuality with her 600 page, Vice Versa: Bisexuality and the Eroticism of Everyday Life in which she argued that most people would be bisexual if not for "repression, religion, repugnance, denial, laziness, shyness, lack of opportunity, premature specialization, a failure of imagination, or a life already full to the brim with erotic experiences, albeit with only one person, or only one gender."[12]
