52% doesn't get it, especially when both were raised in the same household.
It shows that if one identical male twin is gay, then the other twin will probably also be gay -- whether raised in the same family or raised by different families.
Raised by different families is hardly controlling. A portion of those families could certainly produce the same causes to turn a child to homosexual identity crisis, especially if it is a "foster home" of the kind used by child welfare agencies.
But the percentages are indicative. I've seen much smaller percentages from different studies. But it should be much higher if genetically caused. Interestingly enough, the sibling studies are the foremost presented evidence that homosexuality is not genetic.
Actually, the overwhelming evidence is that after, at the very least, 400 generations, we have about the same amount of homosexuality with us today. Homosexuals tend to avoid heterosexual contact and so don't reproduce, except minimally.
Genetically, less than 400 generations, even if some homosexuals overcame their aversion and reproduced, is plenty of time to wipe the practice from the human race.
But, from the foundation of the controversy, homosexuality is antithetical to the very paradigm of mammalian architecture on Earth. The only instances of "homosexual" behavior in animals is when the animals in question are in a highly stressful and atypical environment, or they "practice", much like a dog humping your leg.
I just can't see the overwhelmingness of it, unless it is what one wants to believe. Is that what you want to believe?