Testosterone is important not only to develop big muscles but it is also crucial for the development of sexual characteristics, ie to become a man. Without this hormone, all XY fetuses will become like the picture of today. This applies to all mammals. They begin their development towards becoming women/females but in XY fetuses a testosterone shower will come. In humans, at six weeks of age. This shower forces the development on a different track and it becomes a man / male. The testosterone comes from a gland in the fetal body that develops early and then become testes. The opposite is also possible. An XX fetuses may have been exposed to too much testosterone and then it will be a man, even if chromosomer set is XX.
Prospective physicians must consider this situation. Imagine you're sitting there as a doctor with a woman on a visit and she comes to you because she does not get pregnant. She wonders why, and you do a number of tests routinely. You also tests her genetically, the chromosomes she has. The answer from the lab is that she has XY set in terms of sex chromosomes and that she is sterile. What do you say to her then? Are you going to say bluntly that she is genetically a man?
The recommendation for medical student is that you have to be careful with the information and maybe say something like "sorry you have a chromosome damage so you can not have children." Now this is not very common but it does occur.
What has happened is that there has been a mutation that made the cell receptors for testosterone immune and the testosterone message can´t get forward and then the development continue along the basic pattern to make a woman. A woman with a female brain and a full female body apart from a couple of dwarf testicles that may appear in a woman's labia.
The biological significance of gender development has begun to be denied from a certain direction. Gender research do not agree that sex is a biological construction. Sex says it is a social construction. "Gender researchers' mean then that the children should grow up with gender-neutral toys. As a biologist, I can´t understand this and most people experienced in life think it is obvious that it is biology that determines.
Sex is determined by biology but considering that all begins its development towards becoming a women / female and for it to be males, the development must change onto another track with the help of hormones. It is not difficult to understand that there may be errors in this development. An example of this is that boys are affected more often by different disorders than girls. But you can not just rely on these cases that not completed a full development because then you end up wrong.
Gender-neutral upbringing is written about in the media and some preschools provide gender-neutral upbringing and there you use gender-neutral toys. http://www.sodermalmsforskolor.se/egalia/extern/genuspolicy.htm
A swedish preschool writes on their site.
"We believe that when we in society in general talk about "male" and "female" so are these words heavily influenced by myths about sex. At Egalia believe that the traditional notions of "feminine" and "masculine" has affected humans to separate us according to sex., we find that even small children in the community are aware of the differences in the sexes and what is considered appropriate for girls and boys. This limits as us men and women's in lifes choices and we at Egalia believe we have an important task to change this." "On Egalia all toys, books, materials, and treatment of children and adults thought are from a gender equality perspective."
An ad that tries to be gender neutral. Why is not spiderman pink in his attire?
Personally, I think that all kinds of toys should be available so that kids can choose. Any move to remove toys that are not considered to be gender-neutral will instead discriminate the children.
When one of my daughters once asked for a makeup doll she got it and when my other daughter wanted a tool box she got it also. Besides this, they have both been given both dolls and cars. I think sometimes about the Impact I had on my girls, my oldest girl will be sea captain and my youngest will be a pilot. This they have come up with completely themselves. And instead, I wonder if I will have any grandchildren.