Ok but not all FTM are the result of abuse. Many are but a lot of them when they're very young are related to what we'll call for this- 'I'm not like other girls' syndrome. At 12-ish people start to grow up, puberty is right around the corner, girls begin to notice boys and will often have their first 'boyfriend/girlfriend' in that innocent way that pre-teens often do and a lot of friendships end up breaking down as a result of the changes that occur. Pre-puberty is a transitional time that's very weird, especially for girls. These girls see their friends who've they've always had change and not want to spend so much time cultivating their female friendships, their interests change, their hobbies, it's a huge period of upheaval and for a lot of the FTM girls they fear this change. For those who're already mentally ill in either minor or major form, it's incredibly hard. They don't want to be another of 'those girl' that they used to be part of and close friends with, they want to be the one whose not like all those other girls.
Some double down on being a tomboy, these days it's becoming more common for their answer is to claim they're a boy. That they were 'meant to be born a boy' because their interests don't align with their peers in that age and gender anymore. This is often around when puberty starts and for a lot of them they will begin to emotionally eat as a result of this break in the comfort and normalcy they had in childhood, thus turning some of them into the doughy FTM types if they stick with it. They're emotionally vulnerable and they often don't have a high level of self esteem but no one tells them this is normal, so they assume something is wrong with them and become defensive- rejecting all the well adjusted, girly, pretty, girls who are actually going through the same thing if the truth be told as being an 'other' the one that they 'aren't'.
Abuse can exacerbate it and once they hit puberty being see as a sexual being can exacerbate it too, for some of them other mental illness can contribute. For a lot of these young tumblr types though it's because they've suffered a major break in their world as a result of normal human growth and no longer have the support system they once had. They no longer have the nice teachers who tell them how special they all are, they're just another teen, they often lose their close friendships and attempts to cultivate new ones is incredibly difficult. They don't have anyone telling them it's ok to not be comfortable with your body, your sexuality, etc. instead they find the embrace of online communities and get 'turned' by people and the appeal of the LGBT+ community, what seems to be a new support system and 'belonging'. They have people who tell them their differences are 'this' providing them with labels they can use to be a badge to show how they're special and different and having outside influence is an easy way to scapegoat their problems, instead of facing them and dealing with them to move forward.
