Introduction / Kevin Howells -- The homosexual preference / Philip Feldman -- Homosexual behaviour in animals / P.A. Tyler -- Gender identity and sexual behaviour / Harry Brierley -- Fetishism, sadomasochism and related behaviours / Chris Gosselin and Glenn Wilson -- Coercive sexual behaviour / Kevin Howells -- Sexual inadequacy / Derek Jehu -- Impairment of sexual behaviour in non-human primates / Derek Jehu -- The assessment of diverse sexual behaviour / D.R. Laws -- Sexual diversity, a sociological perspective / Ken Plummer.