Ask this question, and you will probably receive one of two responses: People choose to be gay. They are making an immoral choice, which government should discourage. Sexual preference is biologically determined. Government should protect gay people from discrimination because homosexuality is an unalterable aspect of their identity.
These two answers have something in common: With both of them, the science conveniently supports the moral decision. How wonderful it is that nobody has to be gay! Isn't it fantastic that, by an amazing coincidence, there is no way to stop it? Perhaps sexual preference can be changed - and people have the right to engage in gay sex and have homosexual relationships if they choose to do so. The fourth option, Is sexual orientation a choice yahoo weather gay people have no choice but to be gay, but should be punished for it anyway, is morally unthinkable.
What does science tell us sexual preference? Genes We know, from many twin and adoption studies, that sexual preference has a genetic component.
A gay man is more likely than a straight man to have a biological gay brother; lesbians are more likely than straight women to have gay sisters. Ina study published in the journal Science showed that families with two homosexual brothers were very likely to have certain genetic markers on a region of the X chromosome known as Xq This led to media headlines about the possibility of the existence of a "gay gene" and discussions about the ethics of aborting a "gay" fetus.
There have also been headlines about an "alcoholism gene", which makes people become alcoholics, and a "warrior gene", which makes people unusually aggressive. Genes can't control behavior completely, though. Genes regulate the production of amino acids, which combine to form proteins. The existence or absence of a protein can have an effect on things like alcohol tolerance or mood.
Affecting something is not the same as having complete control over it. Environment, like genetics, plays an important role in how our behavior develops.
Alcoholism runs in families not only because there is a genetic component to alcoholism, but also because children learn how to cope with stress by watching how their parents and their older siblings behave in stressful situations. If you come from a culture where alcohol consumption is forbidden, it will be difficult for you to become an alcoholic, no matter how your body metabolizes alcohol.
There are factors besides a "warrior gene" that contribute to aggression. Children learn to behave Is sexual orientation a choice yahoo weather when they witness aggression being rewarded. If you grew up in a family or as part of a culture where aggression was not well accepted, you would be less likely to be aggressive.
You would learn, from an early age, how to control your aggressive tendencies. Your environment affects your sexual and romantic relationships. Throughout history, marriages have been influenced by family relations and by economic needs. People adhere to cultural constraints of monogamy despite being attracted to people other than their spouses. Your culture affects your views on homosexuality. In some societies, homosexuality is accepted, in others, it is frowned upon but tolerated, in yet others, it is a serious criminal offense, possibly punishable by death.
Male homosexual behavior was expected in ancient Athens. Today, ritual male homosexuality plays an important role in some cultures in New Guinea. Your upbringing can influence what you find desirable and what you find repulsive. Most Americans would be probably be nauseated if they learned that, when they thought they had been eating beef, they were, in fact, eating dog, even though there is nothing inherently unhealthy about dog meat.
What you have learned about homosexuality as you were growing up will affect whether you consider engaging in homosexual acts to be desirable or disgusting. Some people might argue that if you are "genetically gay" but the thought of homosexuality nauseates you, then you just haven't accepted the fact that you really are gay.
That argument is based on the assumption that sexual preference is purely biological; therefore, it has no place in a discussion about the possible causes of homosexuality. The Brain The structure of the brain might influence sexual preference. Ina study published in the journal Science seemed to show that the hypothalamus, which controls Is sexual orientation a choice yahoo weather release of sex hormones from the pituitary gland, in gay men differs from the hypothalamus in straight men.
The third interstitial nucleus of the anterior hypothalamus INAH3 was found to be more than twice as large in heterosexual men as in homosexual men This study was criticized because it used brain tissue obtained at autopsies, and all of the homosexual subjects in the study were believed to have died of AIDS. This study, which also used brain tissue from autopsies, did not reveal any significant difference between the size of the INAH3 in gay men and straight men. It did, however, show that in gay men, neurons in the INAH3 are packed more closely together than in straight men.
PET and MRI studies performed in have shown that the two halves of the brain are more symmetrical in homosexual men and heterosexual women than in heterosexual men and homosexual women.
These studies have also revealed that connections in the amygdalas of gay men resemble those of straight women; in gay women, connections in the amygdala resemble those of straight men. The amygdala has many receptors for sex Is sexual orientation a choice yahoo weather and is associated with the processing of emotions. Some studies have shown that the corpus callosum - the main connection between the two halves of the brain- has a different structure in gay men than in straight men.
However, other studies have found no difference. Gay women and gay men are more likely to be left-handed or ambidextrous than straight women and straight men, according to a number of different studies. Some researchers have suggested that this difference in handedness - preference for one hand over the other can be observed in fetuses - is related to differences in the corpus callosum. A study showed that the anterior commissure, a smaller connection between the brain's two hemispheres, is larger in homosexual men than in straight men.
However, according to a study that was performed ten years later, the size of the anterior commissure is not affected by sexual orientation.
We know from studying rats that exposure to sex hormones in the womb during a critical period in brain development affects future sexual orientation. By manipulating hormone levels during this time, scientists can make rats engage in homosexual behavior later on.
So your brain was influencing your sexual preference even before you were born. This can explain why many gay people feel that they have always been gay. Brain development does not stop at birth, though.