Are boys and girls wired differently?

On Snikollet's post "Girls and Boys" she wrote about the book The Dangerous Things for Boys by Conn Iggulden, and I posted this comment:

My observation: I had identical twin daughters in 1960 and a son in 1963. I gave the girls trucks and cars and my son dolls, which eventually became G.I. Joes at his insistance. I was determined that MY children would not be limited to the stereotypes.

You would think that my son, having his two sisters as examples, would follow in their footsteps. However, he had some inner urgings of a different type.

The girls, while playing with their little cars and trucks, would talk their way from place. "And now we are crossing the river and going down the road and turning the corner and stopping at Grandma's house, and now we are getting out of the car and walking to the door and knock-knocking on the door, and now we are leaving Grandma's house and getting in the car to go to the store, and now we ..." My son picked up his car and said, "Rowrrrr, rrrruuummmmmmMMMMM, bang! Squeeeeeelllll, arummm-rummm-mmmmm screeeeeechhhh, boom!" The girls cuddled their dolls, while my son tied his to a parachute and threw it off the deck to see if it would float slowly down.

Before he could walk, my son would push the pedal-fire-engine along the patio (his legs were too short to sit in it and pedal). When he approached the edge, he would hold onto the side of the vehicle so he could "walk" to its middle, turn the steering wheel, hold on as he inched his way back behind it, push until it turned, inch his way back to the steering wheel, straighten it, and return to the back to push it along this other edge of the patio. Where did THAT come from? The girls never did that. Was he simply as brilliant as his mother (moi) thought? My son's wife has thanked me for raising such a sensitive and loving person, but I wonder how much was already there when he was born.

My daughters are also loving and kind while not fitting any stereotypes. One of the twins is married to a banker; before they had children, when each of them drove vehicles they chose for themselves, her banker-husband drove a conservative black sedan, while she chose a red truck with rollbar and lights. Also pre-motherhood, the other twin daughter hauled a boat behind her work vehicle so she could launch it into lakes in order to motor out and get samples of the water for testing.

I think I accomplished my goal of raising self-reliant and sensitive adults, but nurture and environment definitely combined with something each was born with.