I’ve actually been looking for it in expectation of the request; the foremost source on the matter which I’m aware of is from a Norwegian study group which arrived at its conclusions a few years ago. Norway is quite progressive on the subject, currently allowing children to determine their own gender, but I am having trouble finding ANY Norwegian studies right now - “child gender study toys norway”, for example, results in page after page of commentary videos and articles on the subject of the law itself. Next to no discussion of the academia behind it.
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