[Maelstrom]

Homosexuality is highly correlated with a number of environmental factors.

These factors are not universally found, but include and are not limited to: Sexual abuse at a young age, Sexual abuse at adolesence, low self-esteem, addictive behavior, seduction in the formative years, and generally being taught that physiological ejaculation is the same as orgasm with the albatross: "It wouldn't have happened if you weren't gay."

Which should almost completely describe why the incidence is 50% in twins (both do not always suffer one or more of the above, but will, about 1/2 the time) and not 2%, nor 100%.

It is a *learned* behavior, and as the screening of gay parents reaches to people more likely to act against the children they have or adopt, the incidence will rise.