What are the chances of being gay

Recently there's new evidence that being LGBT is partially heritable but can be affected by environmental factors (discovered using twin studies). Without knowing the proximate causes I'm not sure this is a legitimate exercise. Check compound probability and independence of events. Scientists may have finally solved the puzzle of what makes a person gay, and how it is passed from parents to their children.

A group of scientists suggested Tuesday that homosexuals get that. Studies have found that a man without older brothers has about a 2 percent chance of being gay, but one with four older brothers has a 6 percent chance. (Meanwhile, other studies have found. Over recent decades, studies have shown that American society has grown more welcoming or accepting to members of this community, however discrimination based on sexual orientation and gender.

How many people are gay in the world

Percentages of children of gay and lesbian parents who adopted non-heterosexual identities ranged between 16% and 57%, with odds ratios of to , depending on the mix of child and parent genders. Scientists don't know the answer to this Darwinian puzzle, but there are several theories. This article is more than 10 years old. Table 2 and Figure 2.

His lab had previously shown that gay men in Japan were no more attentive or generous towards their nieces and nephews than straight, childless men and women. And even if heterosexual sex is more advantageous in evolutionary terms than gay sex, it's not only gay people whose sexuality is determined by their genes, he says, but straight people too. For Qazi Rahman, it's the media that oversimplifies genetic theories of sexuality, with their reports of the discovery of "the gay gene".

Vasey hasn't yet measured just how much having a homosexual orientation boosts siblings' reproduction rate, but he has established that in Samoa "gay" men spend more time on uncle-like activities than "straight" men. In a issue of Science magazine , geneticist Andrea Ganna at the Broad Institute of MIT and Harvard, and colleagues, described the largest survey to date for genes associated with same-sex behavior.

Edition: Europe. Listen again to the programme on iPlayer or get the Why Factor podcast. Kinsey did not believe that sexual identity was fixed and simply categorised, and perhaps his most lasting contribution was his scale, still used today, in which individuals are rated from exclusively heterosexual to exclusively homosexual on a scale of 0 to 6. He believes that sexuality involves tens or perhaps hundreds of alleles that will probably take decades to uncover.

The implication is that there is an unknown mechanism in the X chromosome of men's genetic code which helps women in the family have more babies, but can lead to homosexuality in men. Copy link Facebook Twitter LinkedIn. Male mice lacking TRPC2 no longer display male-male aggression, and they initiate sexual behaviors toward both males and females. It's becoming scientific orthodoxy. These results haven't been replicated in some ethnic groups - but that doesn't mean they are wrong with regards to the Italian population in Camperio-Ciani's study.

He acknowledged that people could move on the scale during their lifetime, and indeed Kinsey himself is said to have moved from a 1 or 2 when younger to a 3 or 4 in middle age. The allele - or group of genes - that sometimes codes for homosexual orientation may at other times have a strong reproductive benefit. Because, if we consider possible transient same-sex behaviour, his rather wild stat-in-the-dark begins to look rather reasonable.

William Rice, from the University of California Santa Barbara, says that it may be possible to explain this by looking not at our genetic code but at the way it is processed.

Every now and then a family member receives a larger dose that affects his or her sexual orientation, but the allele still has an overall reproductive advantage. But, just as in the UK, the routine US National Health Interview Survey NHIS comes up with a lower figure for bisexuality than the dedicated sex surveys: it seems plausible that there is less willingness to acknowledge bisexual identity in routine surveys, whereas those who clearly identify themselves as gay or lesbian are willing to be more upfront.

It's not all in the DNA. As the ease and affordability of genome sequencing increased, additional gene candidates have emerged with potential links to homosexual behavior. When it became necessary to predict what would happen to the Aids epidemic, it was vital to find out what people actually did with each other.

Stop calling it a choice: Biological factors drive homosexuality

But this is not all just girls kissing girls in imitation of Madonna and Britney Spears; around half report genital contact, and around half of these in the past five years, so that overall nearly one in 20 women report a same-sex partner in the past five years. Rice and his colleagues refer to the emerging field of epigenetics, which studies the "epimarks" that decide which parts of our DNA get switched on or off. Numerous studies have established that sex is not just male or female.

Gay people were 'helpers in the nest'.