There has been numerous tests to see if people are born lgbt by gays and heterosexuals and no one has found any gay gene or biological determinant within the human body that determines your sexuality. These tests all conclude that the only way possible to be homosexual or lgbt is through social and physical environmental determinants. Some of these tests include "1991 Hypothalamus (Brain) Study, Simon LeVay, who self-identifies as gay, said: "It's important to stress what I didn't find. I did not prove that homosexuality is genetic, or find a genetic cause for being gay. I didn't show that gay men are born that way, the most common mistake people make in interpreting my work. Nor did I locate a gay center in the brain."
"1991 Twins Study, Richard Pillard – also a gay man – admits: "Although male and female homosexuality appear to be at least somewhat heritable, environment must also be of considerable importance in their origins."
"1993 X Chromosome Study, Dean Hamer – also a gay man – said: "…environmental factors play a role. There is not a single master gene that makes people gay…I don't think we will ever be able to predict who will be gay."
"2005 Fruit Fly Study, Barry Dickson, the lead researcher, admitted that the understanding of how innate behaviors are genetically determined is "rudimentary at best." He also admitted that the male-male courtship behaviors they observed probably involved "environmental and social stimuli" and that the female-female courtship behavior was abnormal – missing some key steps."
"If being gay is a choice, when did you decide to become straight?" is the general argument here. People aren't born with any incentive to be straight or gay. We perceive what is shown and taught while we mature, then it is up to us to decide what/how we want to feel (whether or not it defies what was instituted in the first place). You choose to go left or right, upstairs or downstairs, in or out, fight or walk away, gay or straight.