Certain Brain Scans Show Similarity Between Gay Men, Heterosexual Women

According to new research, brains scans of areas associated with
emotion and mood showed that gay men and heterosexual women displayed
similarities, as did comparisons between lesbians and straight men. The
specific focus was on the amygdala, a part of the brain located in the
limbic system that is associated with the processing of emotion. From
the article:

Brain scans of 90 volunteers showed that the brains of heterosexual men
and homosexual women were slightly asymmetric with the right hemisphere
slightly larger than the left, Ivanka Savic and Pers Lindstrom wrote.
The brains of gay men and heterosexual women were not.
Then they measured blood flow to the amygdala -- the area key for the
"fight-or-flight" response -- and found it was wired in a similar
fashion in gay men and heterosexual women as well as lesbians and
heterosexual men.

Also noted in the article is that even though the scans suggest
similarities in how the brain functions between the aforementioned
groups, it doesn’t really tease out whether these findings are the
result of biology, environment, hormones, etc. Basically, we are still
at the original question - do our preferences, likes/dislikes, etc.
result from our biology, hormones, environment, or (as most likely) a
combination of all of the above? How a brain looks and functions as an
adult is not definitive evidence it has always looked that way -
environmental influences and the processing of experience has been shown
to alter brain functioning. However, research like this will certainly
open the door to further research in just how our brains work and
develop, including in such areas as sexuality.