Gays and Straight Women Have Similar Brains

The brains of the homosexual men and women look similar to those found in straight people of the opposite sex, scientists revealed.

Study conducted at the Stockholm Brain Institute examined the peculiarities of the brain's halves in 90 participants of different sexual orientation. The findings suggest that lesbian women and straight men had the bigger right size of the brain and gay men and straight women had both halves of the brain of the same size.

Though, the results do not indicate that the size of the brain halves is related to behavior, it can be connected to the processes that take part during fetal and postnatal development.

During the research scientists used MRI (magnetic resonance imagery) to study two different characteristics that were not influenced by such factors as behavior or learned skills. As much as 90 gay and straight men and women took part in the research. Fifty participants were also examined with the help of positron emission tomography (PET) scans to explore the amygdalae area, , masses of nuclei found within the temporal lobes that are responsible for emotional response, arousal, fear feelings and hormonal secretions.

The findings showed that straight men and lesbian women had bigger right-hand brain hemisphere, while gay men and straight women had proportioned brain hemispheres.

Scientists also found another peculiarity in amygdala connections that was the similar for lesbian women and straight men.

The amygdale plays an important role in emotional response to different stimuli, like stress. And while heterosexual men are more inclined to have a "fight-or-flight" reaction to external stimuli, homosexual women are likely to have similar response.

The results of study can be helpful in finding a clue to future sexual orientation early in life.