Since the matter of choice is rather interesting to me, it is hardly a shock that I would be interested in the question of whether or not sexual orientation is a choice. One obvious problem with trying to settle this matter is that it seems impossible to prove (or disprove) the existence of the capacity for choice. As Kant argued, free will seems to lie beyond the reach of our knowledge. As such, it would seem that it could not be said with confidence that a person’s sexual orientation is a matter of choice. But, this is nothing special: the same can be said about the person’s political party, religion, hobbies and so on.
Laying aside the metaphysical speculation, it can be assumed (or perhaps pretended) that people do have a choice in some matters. Given this assumption, the question would seem to be whether sexual orientation legitimately belongs in the category of things that can be reasonably assumed to be matters of choice.
On the face of it, sexual orientation seems to fall within the realm of sexual preference. That is, in the domain of what a person finds sexually appealing and attractive. This seems to fall within a larger set of what a person finds appealing and attractive.
At this time, it seems reasonable to believe that what people find appealing and attractive has some foundation in neural hardwiring rather than in what could be regarded as choice. For example, humans apparently find symmetrical faces more attractive than non-symmetrical faces and this is not a matter of choosing to prefer one over another. Folks who like evolution tend to claim that this preference exists because those with symmetrical faces are often healthier and hence better for breeding purposes.
Food preferences probably also involve hard wiring: humans really like salty and sweet foods and the usual explanation also ties into evolution. For example, sweet foods are high calorie foods but are rare in nature, hence our ancestors who really liked sweets did better at surviving than those who did not really like sweets. Or some such story of survival of the sweetest.
Given the assumption that there are such hardwired preferences, it is conceivable that sexual preferences also involve some hardwiring. So, for example, a person might be hardwired to have a preference for sexual partners with light hair over those with dark hair. Then again, the preference might be based on experience—the person might have had positive experiences with those with light hair and thus was conditioned to have that preference. The challenge is, of course, to sort out the causal role of hard wiring from the causal role of experience (including socialization). What is left over might be what could be regarded as choice.
In the case of sexual orientation, it seems reasonable to have some doubts about experience being the primary factor. After all, homosexual behavior has long been condemned, discouraged and punished. As such, it seems less likely that people would be socialized into being homosexual—especially in places where being homosexual is punishable by death. However, this is not impossible—perhaps people could be somehow socialized into being gay by all the social efforts to make them be straight.
In regards to hardwiring for sexual orientation, that seems to have some plausibility. This is mainly because there seems to be a lack of evidence that homosexuality is chosen. Assuming that the options are choice, nature or nurture, then eliminating choice and nurture would leave nature. But, of course, this could be a false trilemma: there might be other options.
It can be objected that people do chose homosexual behavior and thus being homosexual is a choice. While this does have some appeal, it is important to distinguish between a person’s orientation and what the person choses to do. A person might be heterosexual and chose to engage in homosexual activity in order to gain the protection of a stronger male in prison. A homosexual might elect to act like a heterosexual to avoid being killed. However, this choices would not seem to change their actual orientation. As such, I tend to hold that orientation is not a choice but that behavior is a matter of choice.