Offers research findings and theoretical interpretations of research into biological contributions to variations in sexual orientation, based on the premise that such orientation can be fully understood only within a biological context. Covers genetic and perinatal influences and neurological and physiological aspects. The 11 papers are from a summer 1995 international symposium in Minot, North Dakota. The symposium also considered biological contributions to sex-typical behavior, the papers on which are to be published by Praeger in 1998 as . Includes a name index without phone numbers. Annotation c. by Book News, Inc., Portland, Or.