Quote from: suzifrommd on September 17, 2015, 08:04:16 PM
I don't read much into this study. This is only peripherally related to transgender humans. I haven't come across any evidence that an animal can be trans. Not surprising, since our brain development is drawn out over a much longer period of time, whereas animal brains develop much more quickly. In humans, the difference between body sex development, and brain gender development is several months. Ferrets, on the other hand, are only pregnant for less than a month and a half.
Obviously you can't ask an animal what gender it identifies as, but there's plenty of research in which animals had their "brain sex" (and later adult behaviour) altered by prenatal exposure to external hormones. The best paper I've found so far discussing these experiments is this one:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3146061/?tool=pubmedwhich is mainly about the research carried out on Rhesus monkeys (which are one of the closest animal models to human beings). It explains the organizational-activational theory of hormone action (there's an organizational phase early in life during which hormones direct you to develop as male or female; later in life, these same hormones have "activational" effects, in which they bring to life all the stuff that was laid down during the organizational phase).
There's also quite a lot of research, with basically similar findings, that was carried out on sheep (sheep are a good animal model to work with, since they're a lot cheaper than Rhesus monkeys; they have several easily observed sexually dimorphic behaviours; and their gestation and the fact that their brain masculinization is through androgens rather than estrogens, is similar to us too).
In nearly all those experiments, they've caused male brain development in biological females by injecting testosterone (or DHT) into the pregnant mother, probably because this is much easier to do than castrating or otherwise shutting down testosterone production in a male fetus. However, one early discovery was that surgically castrating male rats at the appropriate point in their development produces rats that, as adults, look male but behave as if they were female. So it does work both ways.
It's true, we are much more vulnerable than most animals to having our sexually dimorphic brain development go wrong, due to the fact that, in us, the vulnerable period for brain development is so long compared with that for genital development (for that reason alone, you'd expect there to be several times as many trans people as intersex people).
