Scientific studies of gender and sex differences

There is an intense debate on sex and gender differences going on at the moment, both over at Crossdreamers and Crossdream Life.

Here is a list of blog posts covering science on sex and gender that might be of interest:

The evolutionary advantages of feminine men and masculine women
What brain science says about M2F transsexuals
Genes, hormones, sex and gender identity
Two bizarre science stories about sex and gender 
On the statistical difference between men and women
On crossdreaming, Asperger and Klinefelter
New study indicates that female chromosomes may make males more masculine
The bigender sex switchers

Study on differences in mental health between homosexual and heterosexual transsexuals
The female and male copulation instincts 
The Vernon Coleman study of Crossdressers
What is feminine and masculine anyway?
Do male to female transsexuals react differently to erotic material than cisgendered men?
Spanish brain scan study shows male to female transsexuals to be different from men
Infidelity gender equality: They myth about the chaste women
Female to male crossdressing among red deer
Genes, hormones, sex and gender identity
Sex, gender and nature
Gay animals