I have asked this question to 20 or more of the Ladyboys that I know. Every single one of them has responded that they have always believed they were female - from as early as they can remember in most cases.
I also ask them about composition of their family unit (i.e. brothers & sisters) and it doesn't seem to matter. So it's not environmental factors - like one boy with all sisters, so he starts acting like a girl.
Last week I met two sisters who were originally brothers. The eldest always knew she was a girl. Whereas the youngest did admit to deciding based on seeing what the eldest did. That was a first!
In Thailand, Ladyboys are everywhere. There is no advantage here to changing your life so radically, in fact it makes life so much tougher for them. They are often alienated by their families - especially their Fathers. Society tolerates them but equal opportunities does not really exist here and so it certainly limits career opportunities.
So, why so many? Why so prevalent in Asia but less so in other areas of the world?
You could argue that it's 'easier' for Asian features & physique to be feminine and therefore more do - but it's more deep rooted than that.
I understand that in certain areas of Thailand every village and sometimes every family contains at least one ladyboy. It's almost a genetic disposition that is prevalent here. Also, from what I hear, it's increasing.
For that I am truly thankful!