What does it mean to be an individual? As children, we learn that each snowflake is unique; the same shouldn't be so difficult to imagine when we look at people. None of us likes being falsely perceived and mistaken for someone other than ourselves. Who we are not is often as important as who we are.

With the progress of science, we are increasingly able to differentiate the subtle distinctions of individuality. In particular, brain science and genetics have exposed previously unseen layers of complexity. Contemporary research utilizing the most current science has allowed researchers to dispel stereotypical myths about what it means to be a person who is attracted to someone of the same sex. A discussion of two such myths follows.

Most pedophiles are gay

Nope. The American Psychological Association (APA) explicitly states that "homosexual men are not more likely to sexually abuse children than heterosexual men are."

According to the APA, accurate statistics on the prevalence of child and adolescent sexual abuse are difficult to collect because of issues of underreporting as well as the lack of a single definition of what constitutes sexual abuse among minors. The National Institute of Justice conducted a telephone survey that consisted of a national probability sample of 2,000 children between the ages of 10 and 16 for a report on Child Sexual Molestation. The survey found that 3.2 percent of girls and 0.6 percent of boys had suffered, at some point in their lives, sexual abuse involving physical contact. Other more recent reports often mingle child abuse, child sexual abuse, and child neglect. In a 2011 study, the U.S. Department of Health and Human Services found that 27.4 out of 1,000 children were abused in some way; three-fifths (61.0%) of the perpetrators neglected children, 9.7 percent physically abused children, 6.2 percent sexually abused children, while another 15 percent were associated with more than one type of maltreatment.

It is true that possible biases against reporting homosexual encounters exist; a young boy might be less inclined than a young girl to report molestation for any number of reasons. That said, the comparative ratio of boys and girls who report molestation, the frequency of repeat offenders, and other factors suggest to those who have studied the matter that, even when compensating for underreporting, the number of same sex molesters would still be far less than opposite sex molesters. A majority of sexual offenders are men, family members, or in some way acquainted with the child. Women cannot be entirely excluded from the population of sex offenders as there are infrequent cases of women who molest children.

Research by A. Nicholas Groth, who has written extensively about sexual abuse, finds that there are two types of child molesters: fixated and regressive. The fixated child molester would not be considered homosexual or heterosexual because he often molests children of both sexes as he finds "adults of either sex repulsive." On the other hand, regressive child molesters are generally attracted to other adults, but may "regress" to focusing on children when confronted with stressful situations. Groth also found that the majority of regressed offenders were heterosexual in their adult relationships.

Sexual orientation is a choice

Evidence continues to mount that same-sex attraction is genetic... at least partly.

To test whether genes play a role, researchers have compared identical twins (in which all genes are shared) to fraternal twins (in which about 50 percent of genes are shared). One review of twin studies reported that almost all found identical twins were significantly more likely to share a sexual orientation (either both are gay or both are straight) than fraternal twins. Other research demonstrates that there is greater chance of sexual orientation agreement in identical twins than in fraternal twins. If a fraternal gay twin has a brother, there is on average a 15 percent probability that the brother will also be homosexual, but this probability rises to 65 percent in identical twins.

Another study finds that male sexual orientation is linked to markers on the X chromosome, donated by the mother. "X chromosome inactivation" is a process by which one of the two X chromosomes present in a female mammal is inactivated or silenced by it being packaged in a particular and unusual way. Once this has occurred, an X chromosome will remain inactive throughout the lifetime of the cell and its descendants. In one study, researchers measured X chromosome inactivation ratios in 97 mothers of homosexual men and 103 age-matched control women without gay sons. The number of women with extreme skewing of X-inactivation was significantly higher in mothers of gay men (13 percent) compared to controls (four percent) and increased in mothers with two or more gay sons (23 percent). If nothing else, the researchers believe the X chromosome plays a role in regulating sexual orientation in a subgroup of gay men.

Biological effects, such as hormone exposure in the womb, may also affect sexual orientation. In one study, of a sheep population in the western U.S., researchers noted a significant fraction of rams (eight percent) mated exclusively with other males when given a choice between a male or female partner. Factors that could explain male-directed sexual behavior, such as rearing in single sex groups, were ruled out. Researchers examined the sexually dimorphic nucleus of the preoptic area (SDN-POA) of the brain in the rams; this region of the brain is involved in the control of sexual behavior and male-typical partner preferences. In male-oriented rams the structure was shown to be significantly smaller and displayed other distinguishing features when compared to that of female-oriented rams. Ultimately, it was found that the characteristics of this nucleus related to sexual partner preference; the subjects who were attracted to males — both female rams and male-oriented rams — were found to be similar and distinguished from the female-oriented rams.

Although they hypothesize hormones account for these differences, the researchers could not prove that endocrine conditions during prenatal development, specifically testosterone, were the root cause. Nevertheless, the study demonstrates that sexually-differentiated traits are significantly different in homosexual and heterosexual populations in rams. Can it be further extrapolated that what is true for rams is true for humans?

Several brain structures have been shown to be different between men and women. For instance, researchers discovered in the human preoptic area a nucleus they called interstitial nucleus of the anterior hypothalamus number 3 (INAH3) that was significantly larger in men than in women. Subsequent studies showed that INAH3 is significantly smaller in homosexual men than heterosexual men; essentially, its size is equal to what is observed in women. Another study based on different brains confirmed the reduced size of INAH3 in male homosexuals compared with heterosexuals, although the magnitude of the difference observed in this second study was lower than in the original study and not statistically significant. Yet, in this second study, the researchers found that homosexual men had, in the INAH3, a greater density of cells yet a similar number of neurons than heterosexual men.

Scientists believe the existence of a genetic contribution to the control of sexual orientation has been established, even if the specific gene(s) implicated in this process have not yet been identified.

Sources: Balthazart J. Minireview: Hormones and Human Sexual Orientation. Endocrinology. 2011.

Bocklandt S, Horvath S, Vilain E, Hamer DH. Extreme skewing of X chromosome inactivation in mothers of homosexual men. Human Genetics. 2006.