No Scientific Evidence That People Are Born Gay or Transgender, Johns Hopkins Researchers Say
In the three-part report published by The New Atlantis, Lawrence Mayer, a scholar-in-residence at Johns Hopkins University's psychiatry department and a professor of statistics and biostatistics at Arizona State University, and Paul McHugh, a professor of psychiatry and behavioral sciences at Johns Hopkins, take on prevailing claims that sexual orientation and gender dysphoria are caused by natural traits.
Additionally, the scholars challenge the claim that discrimination and social stigma is the sole reason why those with same-sex attractions or transgender identity suffer higher rates of mental health problems.
In the first part, the report argues that there is insufficient evidence to claim that heterosexual, homosexual or bisexual attractions are an innate trait that people are born with.
The report goes into detail about past epidemiological studies that have found a modest association between genetic factors and sexual orientation and behaviors. However, the report states that such studies have not been able to provide significant evidence "pointing to particular genes."
The report also looks at other other evidence of hypothesized biological causes, such as prenatal development and hormones but finds that evidence is also limited.
"Studies of the brains of homosexuals and heterosexuals have found some differences, but have not demonstrated that these differences are inborn rather than the result of environmental factors that influenced both psychological and neurobiological traits," the report reads. "One environmental factor that appears to be correlated with non-heterosexuality is childhood sexual abuse victimization, which may also contribute to the higher rates."
There is actually some evidence that suggests sexual orientation is fluid.
(Photo: Reuters/Peter Nicholls)
The study found that 80 percent of male respondents who had reported same-sex attraction and both-sex attraction in their childhood, later identified as exclusively hetrosexual. Meanwhile, more than half of the females respondents who reported both-sex attractions as children, reported being exclusively attracted to males as adults.
"The idea there that sexual orientation is fluid, that people change as people grow," Mayer told The Christian Post in an interview last Friday. "There are probably some people that identify as hetrosexual that then later on identified as homosexual, so it goes both ways. The importance there is the fluidity and flexibility that these things change in time."
The report also analyzed studies that focused on concordance rates in twins. One study the scholars looked at was a 2010 study from psychiatric epidemiologist Niklas Långström and his colleagues that analyzed 3,826 identical and fraternal same-sex twin pairs.
In analyzing twins pairings where at least one of the twins was same-sex attracted, the report found that only in a fraction of the cases resulted in both twins being same-sex attracted. There was a concordance rate of 18 percent of identical twin males, 11 percent for fraternal twin males, 22 percent for identical twin females, and 17 percent for fraternal twin females.
"Summarizing the studies of twins, we can say that there is no reliable scientific evidence that sexual orientation is determined by a person's genes. But there is evidence that genes play a role in influencing sexual orientation," the report explains. "So the question 'Are gay people born that way?' requires clarification. There is virtually no evidence that anyone, gay or straight, is 'born that way' if that means their sexual orientation was genetically determined. But there is some evidence from the twin studies that certain genetic profiles probably increase the likelihood the person later identifies as gay or engages in same-sex sexual behavior."