"What are you going to tell an 8-year old boy/girl about growing up to be a man/woman?"
Firstly, men and women are both members of the same human race. They look alike in a lot of ways and are a lot alike in a lot of ways. Humans are bipedal, have two arms, two hands, ten fingers, ten toes - and are pretty symmetrical in that their left side looks a lot like their right side. Humans have the same basic needs, food for energy and nourishment, clothing for warmth, and shelter for protection from the elements. Humans are social creatures, they like to belong to their family groups, their communities, to their churches, and even among the fan clubs of their favorite teams. Humans are also intelligent, emotional, creative, and any number of other traits. All of these things are shared between men and women. This is what, egalitarians contend, contribute to the equality of men and women.
Culture shapes who we are and how we live in many ways. Culture tells us what is expected of us as men and women. Culture is fluid - it does change back and forth over time. Were we ancient Grecians, it would be acceptable for men to cry in public. Were we modern Americans, it would not be acceptable for men to cry in public. A few centuries ago, boys would have also worn dresses, the color pink, and blue would have been a girls color. Some cultures say that boys become men at ages 13 or 18 or in their 20s and that girls become women at 12, 13, 15, 18, or in their 20s. We could attempt to put all culturally masculine characteristics on a list, but there is no doubt that there would be quite a bit of overlap with the list made up of all culturally feminine characteristics. Some cultures would agree that men and women are equal, however other cultures would prefer to say that one is superior to the other. In other words, our culture is the nurture side of the gender equation.
The nature side of the equation refers ones biological sex, and is quite distinct from gender. Culturally, young children begin learning gender stereotypes by age 3, they are reinforced by their parents approval or disapproval of any given action. Because of this, it is difficult to create a list of distinctly sex-related traits that manifest in boys only or girls only. But because culture has such a strong impact in some cases sex-related traits can negated by culture, for example, if men are supposed to be hard-wired to not cry, then a crying culture negates that trait. If men are supposed to be hard-wired to cry, then an anti-crying culture negates that trait.
Christians like to be counter-cultural in matters that they agree are against Biblical principle, but when it comes to gender, they are more than happy to enforce cultural stereotypes that the agree are appropriate. The real problem with all of this is that if you are influenced by a two thousand year old stereotype of Godly Masculinity / Biblical Manhood and Godly Femininity / Biblical Womanhood, you find yourself confused as to how to create a list of which is which. In one case, a pastor preached a sermon on why Jesus wore jeans. He was not aware that in Jesus' culture, wearing robes was quite common among men. Today, most men do not wear robes in public. Rather than adopting Jesus' cultural (and Biblical) stereotype of manhood, Christians tend to read modern stereotypes into scripture as well as into teachings about Biblical Manhood and Biblical Womanhood. Being a man or a woman limits who you are to what you do: lead or follow, take or serve, decide or defer, bold or modest, etc. But aren't there times when a wise leader realizes that it is necessary to follow another? When one who serves must in turn be served? When the decision is to defer? When one can be boldly modest or modestly bold? It seems to me that me and women are so much more alike than they are different that it's impossible to define traits and characteristics that are distinctly only masculine or feminine.
So what would I tell a young child about being human? That no matter who or what you are or your particular beliefs, it is always a great idea to respect all people, no exceptions. That being a man or a woman isn't about your age or how well you match a cultural stereotype of what is expected of you. It's about finding out who you are as an individual and being true to your own characteristics. You will know it when you feel it and do not depend upon others to tell you whether you are or you aren't. The truth is, all of us have both masculine and feminine traits - it's called being human. To try to stop masculine traits or feminine traits from manifesting themselves would be an endless battle no one could ever win. It would mean that we would have to give up what it is to be human.