Is Being Gay Genetic? Unbiased Answers & Studies | PhysicsForums

[Antiphon]

Antiphon, I thought you were arguing in favor of a gay gene in the conventional sense. But apparently you believe, as I do, that it's most likely the change in hormones in the uterus from first born to last born that results in higher rates of homosexuality. I agree that it's possible that this is something that evolution has found to be useful in every mother's genetics, but that's far from a settled question. Evolution doesn't do everything perfectly; it makes plenty of design mistakes; and it seems more likely to me that this is one of them than it is a group selection effect.

Yes, many mistakes and dead ends get tried out. But they should get rejected when there's no advantage and a heavy cost. If homosexuality had no evolutionary advantage then I'd think the reasoning about it getting weeded out would apply. It would be tried and rejected, or at least not be expressed so much. It's an expensive thing to have a sizable portion if your population not participate in genetic propagation. It would be as if 2-5% of the population were born sterile. It's too expensive to do unless there's a survival advantage that offsets the cost.

 

[CCWilson]

Whether the survival advantages of adding non-reproductive participators outweigh the cost - that's what I question. Less food for everybody else in exchange for additional warriors and caregivers - I'm not sure how that equation works out.

Just as we peak in our athletic abilities in our early twenties, even though it would be better for personal and group survival to maintain our athleticism, it may be that a woman's reproductive capabilities naturally decline as well, just from wear and tear.

 

[Ken Natton]

These forums discourage mere assertion of opinion and prefer reference to evidence based conclusions. As has been discussed further up this thread, the reality is that the answer to this question remains unknown to science and it is not particularly certain if or when science will know more. But, as seems to be usual with this topic, there are some strikingly obvious false assumptions running through the posts made on this thread since its revival, centrally that homosexuality has anything whatever to do with non-reproduction. Lots of homosexuals have children. The desire to have children and all of the emotions associated with children are actually quite separate from the sexual urge. Again, the overwhelming majority of human sexual behaviour has nothing whatever to do with reproduction.

 

[CCWilson]

Ken, homosexuality would, I'm pretty sure, reduce the number of offspring. I suspect that statistics would bear that out today, as would logic. I'm sure that nobody here believes that homosexuals don't have kids, just fewer. It may not have expressed exactly that way, but we aren't stupid.

Darwin didn't observe evolution occurring. He saw the results after the fact. He didn't do experiments. His theory was a triumph of logic, based on available evidence. The time scale required for evolution of human behavior makes it impossible to observe or to conduct experiments. The best we can do is apply our powers of logic - what were the survival or reproductive advantages that would promote a "gay gene"? What does the available evidence suggest? Evolutionary science is different from other disciplines. If you read the literature, you'll find that most new proposals are speculative and are judged on how well they fit whatever evidence there is.

 

[Pythagorean]

So... why don't you provide the evidence, rather than attaching the word "logic" to it and "stupid" to the opposing view. I don't find that to be very sound reasoning.

 

[Ryan_m_b]

Ken, homosexuality would, I'm pretty sure, reduce the number of offspring. I suspect that statistics would bear that out today, as would logic. I'm sure that nobody here believes that homosexuals don't have kids, just fewer. It may not have expressed exactly that way, but we aren't stupid.

Rather than assume it would be best to look for some evidence bearing in mind the cultural attitudes towards homosexuality throughout human history.

Darwin didn't observe evolution occurring. He saw the results after the fact. He didn't do experiments. His theory was a triumph of logic, based on available evidence. The time scale required for evolution of human behavior makes it impossible to observe or to conduct experiments. The best we can do is apply our powers of logic - what were the survival or reproductive advantages that would promote a "gay gene"? What does the available evidence suggest? Evolutionary science is different from other disciplines. If you read the literature, you'll find that most new proposals are speculative and are judged on how well they fit whatever evidence there is.

This is misleading, of course evolutionary hypothesis can be tested experimentally. That's why we have model organisms.

 

[CCWilson]

Geez, guys. I said that WE weren't stupid, not that anybody else was. And remind me again how we can test human behavioral genetics experimentally. We can do evolutionary experiments on organisms that reproduce thousands of times as fast as we do, but not on humans, especially regarding things as subtle as personality traits and sexual preference. And any conclusions I draw are based on logic, trying to find the best explanation based on the evidence we have - in this case, the increased rate of homosexuality as the number of children increases - with absolutely no value judgments considered or implied.

 

[Pythagorean]

"Logic" or intuition? Our intuition in science is to not trust our intuition without evidence.

To answer your question about measuring behavioral genetics: twin studies

 

[CCWilson]

Darwin's theory was based strictly on logic - and intuition. He came up with an explanation that best suited the evidence. He didn't observe evolution in action. He didn't "prove" anything. Should we throw out his theory?

How do you propose that we prove why certain people are homosexual and others are heterosexual and how genetics are involved?

I think there's a fundamental misunderstanding of how advances in evolutionary theory come about. It all starts with speculation. A premise is proposed, and people examine it to see if it fits the existing evidence. If it makes more sense than previous theories, it becomes accepted. For example, there's a controversy about whether group selection (also called multi-level selection) occurs in evolution - whether certain traits are selected for because they benefit the group rather than the individual. Most experts say no, E.O. Wilson says yes. There are heated discussions about which side best fits the evidence. It's all based on logic, because there's damn little hard evidence.

Should we tell them to all shut up, because nobody can prove it definitively one way or the other? After all, they're just using - horrors - logic?

Oh, and twin studies are part of the evidence, as is the increased rate of homosexuality with additional sons. Still nothing is proved. Should we therefore stop thinking and discussing this issue?

 

[Pythagorean]

That's all well and good to practice in your own institution when writing grants and publishing papers, but at physicsforums, we try to stick to mainstream, accepted, theory.

Anyone can sit around and speculate hundreds of different "logical" explanations, but can you do the initial research and provide evidence? Any number of experts are likely already working on some manifestation of the answer to the question and may have already cleared the logical pitfalls that you might be falling into.

So maybe you provide the right answer, maybe you don't. Who knows? You're just speculating, not providing the actual evidence. It's not about "proving" in the rigid, mathematical sense, it's about providing evidence (time and time again) that supports your assertions. That is where evolution is now, that is why we accept it; not just because it sounded logical to Darwin, but because we've been able to reject a century of null hypotheses through quantitative analysis of the evidence.

 

[CCWilson]

So you wouldn't want no Darwin coming in here with an unproved theory, cluttering up this otherwise pristine scientific bastion.

You seem to be saying that opinions are not to be tolerated here - even evidence- and logic-based opinions; only hard facts will be allowed. That kind of rule would eliminate about 95% of the posts on this forum.

 

[Ryan_m_b]

Darwin's theory was based strictly on logic - and intuition. He came up with an explanation that best suited the evidence. He didn't observe evolution in action. He didn't "prove" anything. Should we throw out his theory?

Please stop referring to evolution as "Darwin's theory". We've had over 150 years of research that has massively expanded on his initial, limited theory.

I think there's a fundamental misunderstanding of how advances in evolutionary theory come about. It all starts with speculation. A premise is proposed, and people examine it to see if it fits the existing evidence. If it makes more sense than previous theories, it becomes accepted. For example, there's a controversy about whether group selection (also called multi-level selection) occurs in evolution - whether certain traits are selected for because they benefit the group rather than the individual. Most experts say no, E.O. Wilson says yes. There are heated discussions about which side best fits the evidence. It's all based on logic, because there's damn little hard evidence.

This borders on misinformation. You seem to be implying that hypothesis can't be tested in evolutionary science, that's just not the case.

So you wouldn't want no Darwin coming in here with an unproved theory, cluttering up this otherwise pristine scientific bastion.

You seem to be saying that opinions are not to be tolerated here - even evidence- and logic-based opinions; only hard facts will be allowed. That kind of rule would eliminate about 95% of the posts on this forum.

No the rules are very clear: no personal theories, unpublished research or crackpottery. The reasons have been explained multiple times in the feedback forums.