Gayness May Be Linked to Conditions in Womb

[therother]

Cellular biologists aren't yet prepared to make conclusions about what happens at the placental barrier and yet a psychologist is? If he had said that the study shows that something other than environment was a factor perhaps in the womb, and then encouraged cellular biologists to study it, then I wouldn't have such a problem with it.

Reading the paper, I don't see him coming to any firm conclusions about issues of cellular biology based entirely on his study, which appears to be a refinement of previous work rather than a new observation. I'm neither a cellular biologist nor a psychologist, so perhaps I'm missing it?

Not sufficient. Where's the study at various ages? Where's the study of mixed male and female siblings? Where's the study of single males with all female siblings? There isn't one.

I'm not sure I follow you here. This is the summary of his results:

Edit: doing a little digging, I find that the article was reviewed and edited by only one person. Dr. Dale Purves who runs the cognitive neuroscience lab at Duke University. So I was right. It wasn't reviewed by biologists, geneticists, microbiologists or any other biologists.

I think you are misunderstanding how PNAS peer review papers. When a paper is submitted Track II (i.e. submitted directly to the journal rather than communicated by an Academy member), it will be designated an editor at PNAS. Dale Purves is an editor for Psychology papers. If the editor accepts the paper is worthy of review (oftentimes after chatting with his colleagues), he'll send it out to at least 2 referees that he deems are both competent and independent of the paper's author. These may well have been in the field of psychology, but it's also possible that the view of a cellular biologist was sought as well. Identities of reviewers are generally not made public, not even to the author of the paper.

In any case, I'd have some questions about his choice of samples, its size, and potential biases. It also strikes me that there's an argument that number of biological sisters seems to have an affect, albeit not as clear cut as biological older brothers. There are also a number of fluctuations in the second figure which aren't explained in the text. One would expect, if it's just the number of biological older brothers that's the key, that these would all be at or around 0, which is not the case. Whether these features are artefacts due to small sample sizes or not is hard to say without access to the raw data, but it does lead me to question the results.