E se tiver um várias irmãs mais velhas provavelmente será apenas levemente afetado...
Rafael 2006/6/30, mascarenhascastro <[EMAIL PROTECTED]>: > WASHINGTON - Men who have several older brothers have an increased > chance of being gay — whether they were raised together or not — a > finding researchers say adds weight to the idea that sexual > orientation is based in biology. > > > The increase was seen in men with older brothers from the same mother, > but not those who had stepbrothers or adopted brothers who were older. > > "It's likely to be a prenatal effect," said Anthony F. Bogaert of > Brock University in St. Catharines, Canada, who did the research. > "This and other studies suggest that there is probably a biological > basis" for homosexuality. > > Bogaert studied four groups of Canadian men, a total of 944 people, > analyzing the number of brothers and sisters each had, whether or not > they lived with those siblings and whether the siblings were related > by blood or adopted. > > His findings are reported in a paper appearing in Tuesday's issue of > Proceedings of the > National Academy of Sciences. > > S. Marc Breedlove, a professor in the neuroscience and psychology > department of Michigan State University, said the finding "absolutely" > confirms a physical basis. > > "Anybody's first guess would have been that the older brothers were > having an effect socially, but this data doesn't support that," > Breedlove said in a telephone interview. > > The only link between the brothers is the mother and so the effect has > to be through the mother, especially since stepbrothers didn't have > the effect, said Breedlove, who was not part of the research. > > Tim Dailey, a senior fellow at the conservative Center for Marriage > and Family Studies disagreed. > > "We don't believe that there's any biological basis for > homosexuality," Dailey said. "We feel the causes are complex but are > deeply rooted in early childhood development." > > There have been a number of attempts to establish a physical basis > "and in every case the alleged findings have been severely challenged > and questioned," he said. > > "If it is indeed genetically based it is difficult to see how it could > have survived in the gene pool over a period of time," Dailey added. > > Bogaert said the increase can be detected with one older brother and > becomes stronger with three or four or more. > > But, he added, this needs to be looked at in context of the overall > rate of homosexuality in men, which he suggested is about 3 percent. > With several older brothers the rate may increase from 3 percent to 5 > percent, he said, but that still means 95 percent of men with several > older brothers are heterosexual. > > The effect of birth order on male homosexuality has been reported > previously but Bogaert's work is the first designed to rule out social > or environmental effects. > > Bogaert said he concluded the effect was biological by comparing men > with biological brothers to those with brothers to whom they were not > biologically related. > > The increase in the likelihood of being gay was seen only in those > whose brothers had the same mothers, whether they were raised together > or not, he said. > > Men raised with several older step- or adopted brothers do not have an > increased chance of being gay. > > "So what that means is that the environment a person is raised in > really makes not much difference," he said. > > What makes a difference, he said, is having older brothers who shared > the same womb and gestational experience, suggesting the difference is > because of "some sort of prenatal factor." > > http://news.yahoo.com/s/ap/20060626/ap_on_he_me/sexual_orientation > > By RANDOLPH E. SCHMID, AP Science Writer Mon Jun 26, 6:27 PM ET > > > One possibility, he suggests, is a maternal immune response to > succeeding male fetuses. The mother may react to a male fetus as > foreign, but not to a female fetus because the mother is also female. > > It might be like the maternal immune response that can occur when a > mother has Rh-negative blood but her fetus has Rh-positive blood. > Without treatment, the mother can develop antibodies that may attack > the fetus during future pregnancies. > > Whether that's what is happening remains to be seen, but it is a > provocative hypothesis, said a commentary by Breedlove, David A. Puts > and Cynthia L. Jordan, all of Michigan State. > > The research was funded by the Social Sciences and Humanities Research > Council of Canada. > > ___ > > On the Net: > > PNAS: http://www.pnas.org > --- Não leve nada pro lado pessoal. Apenas divirta-se. Comentários: www.yahoogroups.com/group/goldenlist-L/messages Newsletter: www.yahoogroups.com/group/goldenlist/messages Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/goldenlist-L/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
