What explains the rising number of children with gender issues?

I have recently read a fascinating new paper, via a Mail on Sunday report, about the growing number of children presenting as transgender to gender clinics. It raises all sorts of questions, and deserves to be read widely and carefully. The paper, published in the Journal of the American Medical Association, can be found – unlike a lot of similar work, for free – here. Among its seven authors are two staff from the Gender Identity Development Service (GIDS) in London, the main NHS clinic for children with gender identity issues, including the service’s head, Polly Carmichael. The other authors include clinicians in Australia and the Netherlands, and elsewhere. The