Sugar and Spice to Snakes and Snails

What are little boys made of?
Snips and snails, and puppy-dogs' tails,
That's what little boys are made of.
What are little girls made of?
Sugar and spice, and everything nice,
That's what little girls are made of.

Some of my old psychology professors would scoff at the "sage wisdom" of that old rhyme, but a recent article on CNN says otherwise:

Boys will be boys, girls will be girls from birth

On a related note, when I was an undergraduate, I worked at a coffee shop near campus for two years. During my time there, I got to know "the regulars": students, townies, and the homeless. One particular regular still sticks out to me. This person almost always wore dark clothing that could not typically be characterized as feminine or masculine and thick-soled black boots. This person's hair was shorn to about a half inch. While it was, at first glance, difficult to discern this regular's gender, their figure was definitely more feminine in nature. After a few months of seeing this person on a regular basis, I found out through a co worker that this person, though chromosomally female, had decided to abandon her gender and all of the outer trappings associated with femininity. She had and lived out the viewpoint that humans control gender and predetermined genetics had no hold on her identity.

I do not know what caused her to think and live this way, but over and over again, according to research and even my own personal experience, she and others who purport this viewpoint are missing the boat-in terms of cognition, emotion, relationships and spirituality. Having spent time with children, most recently nephews and nieces, I've noticed a distinct difference in behavior in accordance with the gender line in many cases. How is it that my nephew knows how to use his voice to "shift gears" without prior instruction while playing with cars and trukcs? Why is it that my niece was obsessed with Strawberry Ortcake (as she used to say) and pranced about wearing fairy wings with no encouragement from her parents? Granted, every child's genetic predisposition and environment lead to variance in behavior. But for the love of pete, let's let boys be boys and girls be girls!