Reddit reviews The Essential Difference: Men, Women and the Extreme Male Brain (Penguin Press Science)

My training is majorly in neuropsychology, and my experience of the field of research is that biology does indeed play a large role in the development of behavior, with varying degrees of impact depending on the environment.

It is incredibly difficult to make solid conclusions about sex and gender differences from cross cultural analysis, as the author rightly identifies, but it is a very valid observation that there are biological differences which are identifiable in child brain development and subsequently personality development.

A citation for much of his article can be found here: https://onlinelibrary.wiley.com/doi/abs/10.1002/ijop.12265

David Schmitt is quite respected in this area, and he writes frequently on similar topics with
admirable scientific balance

Essentially, if you were blinded to the sex and gender of a child, there are metrics you would be able to measure which would allow you to place those individuals along a binomial distribution which would correlate very well with various phenotypical representations of biological sex (not chromosomal sex though).

I have followed the work of Simon Baron-Cohen for years, as he is a world leader in research of ASD, empathy, and more; and his explanation of the biological differences between sex and gender is very astute and identifies the issues with the terminology while still having a foundation in biological origins.

One of his best explanations is written up here,
and naturally his book has more in depth analysis all fully cited

This is not to say that we should all rely on biological determinism, but it is far more accurate to discuss the development of the brain in terms of overall biological potential which is either encouraged or stunted by environmental impacts.

The development of empathy is a good example of this. This is an oversimplification, but it makes it easier to conceptualize.
The majority of people have a potential empathy level of 100, for the sake of the example, and may have a predisposition multiplier of .5 - 2, so a child with a 2 would develop towards their empathy potential faster than a child with a 1.

Children with Autism Spectrum Disorder (a good example since indicators of this develop before birth and therefore are not affected by the ‘environment’ of the parenting) will have a much lower potential empathy level, but may still vary as to how fast they are able to meet their potential

Now, most importantly, children will only be able to meet their potential if they experience the prerequisite environmental nurturing as provided by the carer, and this is most obvious in foster children where there is a breach of this care, and even children with a high potential and a high rate can have develop maladaptive empathy and go on to be diagnosed with BPD, NPD or APD, the zero empathy disorders.

If it's the same Simon Baron-Cohen I'm thinking of, then he doesn't support this memo's arguments. Baron-Cohen explicitly points to biology as a starting point for differences between the sexes, and advocated for the ability of social and cultural change to erase this over maturation. He definitely would disagree with the broad, sweeping generalizations made, too: he constantly points out the 'female' brain is not inherent to only females, the 'male' brain not inherent to males, etcetera. Channeling his work to justify bias against women in the workplace is a very unfortunate distortion.