The debate over the roots of homosexuality is possibly the most contentious manifestation of the “nature versus nurture” argument; gay rights advocates, gay rights opponents, and scientists have all joined the fray, advancing and criticizing different theories. With a new brain imaging study, the “nature” proponents seem to have gained a point in their favor.
Swedish researchers did MRI scans of 50 heterosexual men and women and 40 homosexual men and women and found surprising parallels. The brains of lesbians and straight men were anatomically symmetrical while the brains of gay men and straight women had a larger right brain hemisphere.
The researchers also looked at the amygdala, a part of the brain that’s associated with emotions, and found that straight women and gay men both have more connections between the amygdala and brain regions associated with anxiety and mood disorders. Meanwhile, the amygdala of lesbians and straight men had more connections to the region that controls fight or flight reactions.
