Major News articles about Engendered Species:
The case for 'Nurture', or "It's all learned".
We are all born, equally for male and female, as a 'blank slate' upon which is written, by experience and learning, that which we become. If we are only taught the 'correct' way to live our gender, we will choose the appropriate roles in our lives.
In every society, people assume certain jobs, behaviors and ways of dressing are 'naturally' feminine, and others are masculine. But there is in the world as a whole a lot of variety in social definitions.
The case for 'Nature', or "It's all Biology".
In the womb, we are all female until the age of about 5 weeks. At that time, if certain hormone levels are present, those destined by genetics to be male have their female reproductive organs close, 'grow over' and become male organs.
If, however, hormone levels vary beyond a range, the baby can become male or female, regardless of genetics. An in between state can also occur. The brain is also affected, as at 6 weeks or so, it's structure will grow differently for a male or female, or any point in between.
A person's brain is thus 'wired' before birth, to be an instinctually male or female. This is one's 'gender identity'. This may, or may not, by varying degrees, match a person's 'body sex'. Neither can be changed much by later learning. These variations are why some societies and even languages, have up to 50 different words to name the gender varieties that people see.
So, Nature or Nurture?
Why are people different?
Some believe it is learned, or due to environmental causes.
Still others believe it is due to biological, or medical reasons, otherwise called, 'biological determinism'.
Bruce and Brian Reimer were twin brothers born in Canada in the 1950s. Due to a botched circumcision, medical experts of the 'nurture' school thought that it would be best if Bruce were to be raised, without being told of his past, as a girl, Brenda.
The theory of the time held that since the organs could more easily be made female, being raised as female would make a more happier person--- a 'sameness' between body and mind. This was also an assent to social pressure, (what would the babysitter think?).
Her brother, Brian was a normal, happy male. Brenda, however, led a maladjusted, miserable life. Upon being told on 'her' 15th birthday that 'she' was really a male at birth, he says "a great weight was lifted off me".
He lived a much happier life as 'David', for years. Their story is recounted in the book, As Nature Made Him by John Colapinto.
Later, he committed suicide. Was this because of a conflict between the earlier nurture and the nature? Or was it for not fitting in, not having the male organs, or feeling left behind? Or, it could be for other reasons. We do not know.
This case has rewritten several textbooks. Many now say that any sexual ambiguity in infancy should be 'played out' in life, the person deciding which gender is best for them when mature.