How does an eight year old decide he wants to be a girl?
Jack Alantre

Using implicit and explicit measures, we found that transgender children showed a clear pattern: They viewed themselves in terms of their expressed gender and showed preferences for their expressed gender, with response patterns mirroring those of two cisgender (nontransgender) control groups. These results provide evidence that, early in development, transgender youth are statistically indistinguishable from cisgender children of the same gender identity.

Answer: The same way cis kids do.