Encyclopedia of Opinion

Question: Are people born gay?
Position1 of 4›: Yes, people are born gay
Argument1 of 6›: Epigenetics confirm people are born gay

The same genetic code can be expressed differently depending on chemical changes that take place before birth.

The argument

In 2013, William Rice, an evolutionary geneticist at the University of California, published a paper which linked homosexuality to epigenetics. Despite sharing genetic sequences, in identical twins if one twin is gay, it is more likely that the other twin will be straight than that they will also be gay. This indicates that it isn’t a homosexual gene that determines sexual orientation. However, there is evidence to suggest that homosexuality runs in families. Epigenetics is the only possible explanation that can accommodate the hereditary nature of homosexuality while acknowledging the different sexual orientations of identical twins.

Context

The same genetic code can be expressed in different ways. Chemical changes that alter the way the genetic code is expressed can cause two people with the same genetic construct to behave in very different ways.

Premises

[P1]Identical twins share genetic sequences, yet if one is gay the other is more likely to be straight, showing no single "gay gene" determines orientation. [P2] Still, evidence shows homosexuality runs in families, so it has a hereditary component. [P3] Epigenetics, as William Rice argued in 2013, is the only explanation that accommodates both the heredity and the differing orientations of identical twins. [C] Therefore, because epigenetics best explains sexual orientation, people are born gay.

Counter-arguments

The argument from epigenetics is nothing more than a theory. It has never been supported by empirical data. Just because there is an absence of evidence for other theories does not mean that there is evidence for epigenetics.

Rejecting the premises

[Rejecting P3] There is no evidence for this.