In his new book, How to Be Gay, professor David M Halperin says: 'Gayness is not a state or condition. Gay men and women don't share a place of origin, skin color, socio-economic class, religion, or anything else that would typify their experience. But, then again, maybe they gay community needs some sort of shared experience – outside of the experience of falling in love with a member of the same sex – to bring us together.