In a 1999 paper, Reiner indicates that his data show "that with time and age, children may well know what their gender is, regardless of any and all information and child-rearing to the contrary. They seem to be quite capable of telling us who they are, and we can observe how they act and function even before they tell us.
Deborah Rudacille, The Riddle of Gender: Science, Activism, and Transgender Rights
gender, intersex