I had found many interesting perspectives on reasons why some individuals are homosexual and why some aren't . One of the main causes that is strongly linked to homosexuality is too much or too little of a hormone, and how this fluctuation can affect sexual preference.
People holding the letters to "hormone"
Testosterone in men is needed for the development of genitalia, building of muscles, growth of facial hair, pubic hair, body hair, and mentality. Estrogen in women mainly does the same things as testosterone in men, but is mainly needed for the development of breasts and menstrual cycles. Watch this interesting video for more context.
However, when your body produces too much or too little of either male or female hormones, there are some very noticeable effects
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia, is a genetic defect that happens in some girls where:
“the adrenal glands…enlarge prenatally and produce abnormally high amounts of androgens (male hormones)” (Lippa 122).
With these girls producing abnormally high amounts of male hormones, there are a number of studies that suggest that they CAH girls are often less content with being female and are more interested in being males than non-CAH girls.
Brain Structure Differences
A photo of the human brain...weird, isn't it?
Scientific researchers have also found some significant differences between a homosexual’s brain and a heterosexual’s brain. In a research study done by Dick F. Swaab, the suprachiasmatic nucleus, which regulates a person’s biological clock, is two times as large in homosexual men than in heterosexual men.
Another research study found the right brain hemispheres of lesbians are slightly larger—just like the right brain hemispheres of heterosexual men.