My Dearest Gabriel, 1) The "twins" study is officially named "A Genetic Study of Male Sexual Orientation" by J. Michael Bailey, PhD and Richard C. Pillard, MD. While there is a 1/2 page news article about the study in SCIENCE, Vol 255, 3-Jan-1992, Page 33 ... The original article actually appeared in ARCHIVES OF GENERAL PSYCHIATRY, Vol 48, December 1991, Page 1089-1096. 2) The "brain" study is officially named "A Difference in Hypotalamic Structure Between Heterosexual and Homosexual Men" by Simon LeVay. The original article is in SCIENCE, Vol 253, 30-Aug-1991, pages 1034-1037. See the same issue of SCIENCE, pages 956-958 for "News and Commentary" on LeVay's research. Letters to the editor may be found in SCIENCE, Vol 254, 1-Nov-1991, page 630. 3) Finally, the "cognition" study found on measures of visual-spatial ability where consistent difference have been observed between males and females that male homosexuals fall between the two sexes. "....As if, in some congnitive respects, they are neurologically a third sex." [Of all three studies, one might think that this one would have acknowledged the existence of lesbians since the researcher, in this case, is herself, female. But NO, she didn't.] See SCIENCE, Vol 255, 31-Jan-1992 for a "briefing." This briefing said Sandra Witelson's original article appeared in the "current issue" of PSYCHONEUROENDOCRINOLOGY. Since I was in the library late last night and they were turning the lights out on me, I didn't have time to look this particular article up. The "news and comment" article in SCIENCE regarding LeVay's work, SCIENCE, Vol 253, 30-Aug-1991, page 956-957 also made reference to another of Whitelson's works also in PSYCHONEUROENDOCRINOLOGY, vol 16, page 131. In it, Witelson proposes that the brain is a mosaic of areas that may respond to sex hormones at various time during early development. You may want to find both Witelson papers.... ======================================== Bryan J. Blumberg, The MacNeal-Schwendler Corporation 815 Colorado Boulevard, Los Angeles, California 90041-1777 (213) 259-4914, B_BLUMBERG@MACSCH.COM