"The Week" recently featured an expose on the Afghanistan national guard. These are men, still mostly untrained, who largely spend their days making money off opium confiscation and bribery. And after spending some time with them, the writer noticed that the entirety of them engaged in sexual activity with their fellow male soldiers.
The writer gave no other reasons for this besides an assumption of situation. The men were all packed together in very small residences for long periods of time. They had to share bunks. And the assumption was that this situation led to certain sexual behavior that likely would not have happened outside of this situation among these Muslim men.
This is what I would like to refer to as "situationally gay". There are many women who have been in abusive relationships with men, who then enter into relationships with women. The common argument is that these women were always gay. Perhaps many were. But, why exclude the notion that a psychological shift occurred? These woman, scarred by men, now associate men with violence, and therefore, now seek women as both emotional and sexual companions.
These Afghani soldiers, due to the situation of being bunked very tightly with other men, all ended up engaging in sexual relations with other men over time.
I imagine this theory will not be welcomed by many gay people. But, I'm not sure why. It simply acknowledges a psychological correlation for sexual companionship. It makes no moral judgment. It does not deny a genetic argument. It merely suggests that certain situations can overcome default preference.