Human sexuality is a bizarre and often unpredictable thing. Now that society has moved away from heteronormative expectations, it’s become increasingly apparent that gender and sexuality exist on a spectrum.
Scientists have been studying LGBTQ+ people to see if any factors influence the likelihood of a person falling onto this spectrum. Whilst it’s definitely not a case of one size fits all, they’ve made some interesting findings.
Now, it has emerged that having an older brother increases the likelihood of a man being gay.
Whilst there is no denying that society has become more accepting of LGBTQ+ people, we are still a long way off living in a world where they are not discriminated against. That’s why it is difficult for people to come out to their parents.
Horrifyingly, hate crimes against LGBTQ+ people have increased by 78% in the past five years.
Because the older generation grew up in a world that was less accepting of LGBTQ+ people, they can view having a gay child as a loss, especially if that child is male, as it can often mean that their family name will not be passed onto another generation.
Parents may also fear for the safety of the LGBTQ+ children. After all, there is a chance of them being discriminated against because of their sexuality, and gay and bisexual men account for 70% of new HIV diagnoses in the United States.
Professor Tony Bogaert is a researcher specializing in human sexuality at Brock University, and his team attempted to discover whether the birth order of children had any influence on a person’s sexuality.
When Bogaert and his team discovered that there were a number of identifiable factors that could influence male sexuality, including birth order, they dubbed their findings the “fraternal birth order effect”.
Their findings were published in the PNAS journal, and they revealed that a person’s sexuality could be determined by their chromosomal makeup, disproving early arguments that sexuality was determined solely by upbringing.
A protein called NLGN4Y, which associated with a Y chromosome, can influence a man’s attraction towards a partner.
During a woman’s first pregnancy, the Y chromosome in question is present in her bloodstream, however, because it’s not naturally present in a woman, it’s seen as foreign by her immune system, which subsequently creates antibodies to fight it.
As a result, if a woman falls pregnant with a second son, the pregnancy is not quite the same. The antibodies created from the first pregnancy can enter the baby’s brain, altering development and influencing sexual orientation.
However, the results of this study, though interesting, are not comprehensive, as it was centered around 142 women and 12 men between the ages 18 and 80 years. In addition, as I’m sure you’ll know, not every second, or even third-born male in a family is gay.
So how exactly did they study these people?
Well, the scientists checked for the protein NLGN4Y and the antibodies. They discovered that they were found at their highest levels in women whose younger sons were homosexual, compared to women who’d had heterosexual sons or only given birth to daughters.
“I wouldn’t say we’ve solved the fraternal birth order effect puzzle, but we are getting close to finding a mechanism,” Bogaert said.
Bogaert and his team have claimed that the odds of a woman having a homosexual son increase by 33% with each son they have.
However, it’s not just male sexuality that can be influenced by what happens to a baby in the womb. Female sexuality can be influenced by it too.
reported that women who are exposed to higher levels of the male sex hormone androgen have a higher chance of being lesbians. But unlike men, whose sexuality tends to be geared towards one gender, female sexuality can be influenced by cultural and societal factors as well.
Whilst there is no denying that the science behind sexuality is interesting, it does potentially open would-be parents up to making decisions about whether or not to have children depending on what sexuality they would prefer them to be.
Hopefully, however, we will soon live in a world where LGBTQ+ hate crimes become a thing of the past and that when a person chooses to come out as LGBTQ+ to their parents, they have no fears in the back of their minds about how this might affect their lives.