If One Male Identical Twin Is Gay, the Likelihood That

Multiple Choice

If one male identical twin is gay, the likelihood that the other is also gay is about 50%. By comparison, the likelihood that a gay male's fraternal twin is also gay is closer to 20%. How might a behavioral geneticist interpret these figures

A) These figures indicate the influence of non-shared environmental factors, thereby suggesting a sizeable genetic contribution to male homosexuality.
B) These figures indicate the influence of non-shared environmental factors, thereby suggesting a sizeable environmental contribution to male homosexuality.
C) These figures indicate heritability, thereby suggesting a sizeable genetic contribution to male homosexuality.
D) These figures indicate heritability, thereby suggesting a sizeable environmental contribution to male homosexuality.