Brief Nc due to discussing work:
As a primary teacher for over 15 years, mostly teaching in special schools, the only child I have met with any type of gender confusion was autistic.
They were influenced by tv, simply loved any kind of pink girly stuff. It began very early, wanting to have long hair. It was a love of long princessy hair. I think now everyone would have just said just let him grow it. It grew into wanting to be a girl then he picked up on the whole sex change thing via the media. Lots of rigid thinking; eg I remember having to challenging him about the male football stereotype by showing him pics of the ladies teams before he'd do football in PE.
Behaviour was very different when wearing wigs and dresses; time was built into the day to allow for it. He channelled extreme flouncy stereotypes when dressed up, acting out an act he'd seen in princessy cartoons, it could get quite over the top. But got terribly upset if he couldn't be involved in his passions.
Parents were brill and patient and he was seen by someone in London (probably Tavistock) and decided he was happy in his body, could enjoy anything girls could and later on decided he was gay and just very into fashion.
This was pre iPads and easy access to social media and I do wonder how it would have been different today.
I also remember as a child, a boy being teased for simply wanting to play in the home corner. I remember him crying and saying he wished he was a girl.
If you don't fit the stereotypes around you as a child and it is quite a logical conclusion to think you're in the wrong body. I do believe there is a different mechanism at work with true dysphoria but sadly so much gets so confused due to the strong sex and gender stereotypes society is flooded by.
Different people are vulnerable or immune to peer pressure and social stereotypes; the book, The Afluenza Virus, demonstrates how this plays out with regards to advertising, wanting to "have it all" and the impact on mental health including eating disorders, another type of dysphoria. There was Pacific island who got TV very late compared to the rest of the world; within a few years young women and girls started to get eating disorders whereas previously there had been none recorded. I do think there are similar mechanisms at work, everyone is different in their brain physiology and life experiences; the two together will have an impact on self image etc.