In fact, when we reach Robert Kegan's "self authoring" stage, I believe we can shape our brains to eliminate biological sex differences. According to Kegan, only 21% or so of Americans are at the self authoring stage (in one sample - my guess is that number is high).
Here is a good summary of 4th order consciousness:
We are no longer pushed around by cultural forces but become “self-authoring”. Very few people reach this stage before the age of 40. When they do, they are no longer subject to the scripts of abstraction that they developed earlier in life but are able to chose between multiple abstractions and chose to operate out of meta-ethical frameworks. They are no longer bound by maps of behavior but have become autonomous individuals who are consciously picking and choosing the cognitive structures that they chose to operate within. They are rarely ideologically dogmatic and find they can adopt great plasticity in the ways they function and move within the world and various social groups. They are marching to their own drummer based on their own cognitive map of the world.Within this model, then, we become free to create our own sense of gender - we are not bound by cultural norms and we have some power to transcend our neurobiology.
Some of the comments - and there are a LOT of them - are worth reading, too.
A new attack on the theory of a “hardwired” difference, in the brain, between men and women.
Tradition told us men and women were different. Liberation days told us they were the same.
The best-seller list told us women were from Venus, men from Mars. MRI scans said, we were told, the genders are different in their very brains. And people have acted on that. The single-sex education push, just for one.
Now psychologist and author Cordelia Fine says “no.”
“No,” to the assertion of fundamental difference. Look again at the evidence, she says. Society, she says, still builds the difference in men and women.
We speak with Cordelia Fine about her new book, “Delusions of Gender.”
Cordelia Fine, writer and research associate at the Centre for Agency, Values and Ethics in the Department of Philosophy at Macquarie University. She is author of A Mind of Its Own. Her new book is, Delusions of Gender: How Our Minds, Society, and Neurosexism Create Difference.