You should remove “genetic” from your first sentence and argument. Even if environmental, the issue is what causes what. Easiest example is random developmental noise, which gets assigned to environment.
I read it again and I stand by the original version. You are right that other confounding is possible but this design deals with the special case of genetic confounding. Remaining environmental components are of course not immediately causal but genetic causes can be taken out of the picture and in the specific case of sexual minority mental health they seem to be a major part of the effect in the population.
This is debatable (many cases where h2<0.5 and not just due to measurement error) but I agree with the greater point that it's easier to nail down genetic causes at least in an omnibus fashion. It's always interesting that "the genes" cause something even if we don't know which ones (as in a twin control design), "not the genes" causing something is not interesting until we can say what the specific cause is. The minority stress hypothesis bets on a major single nonshared environmental cause, the priors for anything like that are low, Plomin's paper I linked is a detailed account of what happened when they tried to find nonshared environmental effects big enough to be identified.
You should remove “genetic” from your first sentence and argument. Even if environmental, the issue is what causes what. Easiest example is random developmental noise, which gets assigned to environment.
I read it again and I stand by the original version. You are right that other confounding is possible but this design deals with the special case of genetic confounding. Remaining environmental components are of course not immediately causal but genetic causes can be taken out of the picture and in the specific case of sexual minority mental health they seem to be a major part of the effect in the population.
That’s because genetic causation typically exceeds nonshared environmental causation.
This is debatable (many cases where h2<0.5 and not just due to measurement error) but I agree with the greater point that it's easier to nail down genetic causes at least in an omnibus fashion. It's always interesting that "the genes" cause something even if we don't know which ones (as in a twin control design), "not the genes" causing something is not interesting until we can say what the specific cause is. The minority stress hypothesis bets on a major single nonshared environmental cause, the priors for anything like that are low, Plomin's paper I linked is a detailed account of what happened when they tried to find nonshared environmental effects big enough to be identified.