Children learn from their environments. They learn how to act, they learn how to speak, they start mimicking the adults around them before their first birthday and they never really stop. At some point though as most children mature and he or she comes to the realization that he/she is either male or female they begin to structure their lives based on what they see the adult males and females in their immediate environments doing.
The adults present in a child’s immediate environment are therefore very important. It is important that these adults love the children and guide them when they are in need of guidance. It is important that they understand their role as a role model.
Also many people may agree that children need role models but disagree that the sex of the role modes makes a difference, I say that children need to be shown that they have a crucial and indispensable role to play in family life and therefore within society and so even if sexist roles are not as important to you as they are to me, they do benefit the child because they show him or her that their role is specialized, crucial and indispensable and on top of that sexist roles are efficient.
Is there a correlation between valuing the male female relationship and gender roles??
Currently men and women are different and want different things in each other. With male/female interchangeability men and women have fewer differences. But who or what is more valuable to you? A person who is exactly like you and can do exactly the same things as you, or a person who is different from you and does things that you cannot do?
The obvious answer is we value people who bring something new to the table, so gender roles support relationships and add to their longevity.
Supporting Links (I will add more with time):