There might be something to this. i would love to see a comprehensive assesment of peoples genetic and cromosonal makeup. The privacy implications are troubling however.
Myself, I developed at a fairly normal age, I can grow a beard, I have male pattern baldness, i have a somewhat feminine shape, in as far as I don't have a particularly triangular body shape, and my pelvis is a little deeper than most males. Body hair is sparse on the chest, but for the last 10 years or so, fairly extensive on the back. I regularly get taken for 40-45. I'm actually 56. ( As an aside, my GF got carded twice in the last month, she's 38! )