What I would like to ascertain is this: does your enthusiasm for adherence to established gender roles have to do with your child's attainment of a development into adulthood that is in keeping with his or her biological nature; or is it more about adhering to the accepted roles which you regard as necessary for a child's proper social development? Is this a matter of biology - of what is "natural" for a boy or a girl - or of society - of what is expected of a boy or a girl? Or is it something else entirely?
One of the really strong memories I have is a girl in high school who had a baby, and brought it to school. My Family Living teacher asked her to help her with an experiment. They dressed the baby in pink for half of the day, put a ribbon in its hair, and brought the baby around school. People cooed, and were gentle, and soft to her. Then, the baby was dressed in bib overalls, a blue shirt, and told her name was Robby. Now, people used gruff voices, "Hey, Robby! How's my boy!", handled his rougher, and hit him on the back, as opposed to coddle him.
This has to translate to the child somehow.
In a cool experiment I saw on the Discovery Channel about the different sexes, children were asked to pick out the boys' toys and girls' toys. The chose a tank for a girl's toy, because it was pink and purple. The saddest discovery was that if a doll was mad or frowning, it was considered a boy's toy, and if it was smiling, it was a girl's toy.
I have asked my adult students if men and women are really that different, and they whole heartedly agree. I ask if women cry more than men, and they say, "A man can cry twice in his life - when he is born, and when his mother dies."
That doesn't give men much room to express themselves. So, what do you do, I asked, when a girl breaks your heart, or something disappointing happens, or you are scared? They said, "I get mad." And that's all they have, because that is what they are told is acceptable.
Girls, on the other hand, can cry about a grade, cry about breaking a nail, cry because someone broke up with them. They are allowed to be afraid, to be brave, to be angry, to be happy.
As a gay man that grew up playing jump rope, and not understanding why that was not okay, but okay if I take up boxing, I noticed a lot of fear in heterosexuals. They put pink ribbon in the daughter's hair, even though they have less hair than I do, because it's really unsettling to the parents to have people ask, "Is it a boy or a girl?" It is unsettling for people to see androgenous people, like Tilda Swinton, because the live in a world of black and white, of girls giggling and saying, "I don't know. I'm a girl," and guys being homophobic, and belching out the alphabet. Anyone straying from that "norm" is a threat to their reality.
I would allow my child to just be himself, and instill that value.
However, I will say that it rubs the other way as well. My ex-boyfriend had a nephew who was a typical boy. His sister was best friends with the guy from the Gay Students Association in college, and yet, her boy loved only trains until he was five, then moved on to basketball, and now, is really into math. I once said, "wow, he is the boyest boy I have ever seen," and she looked disheartened for a moment.