Social Selection Theory

Social Selection theory is the idea that a person's or animal reproductive success can be influenced by their social ties. I've heard that it may explain the evolution of homosexuality in human beings. The idea being that homosexuality leads to more diverse social relationships that benefit both homosexual people and their families.

I find this interesting because a common topic of discussion at PFLAG meetings is how a friend or relative's coming out wound up having a surprisingly positive impact on your life. That would seem to agree with the theory.

Here's an interview with the scientist who came up with the theory.