I also want to let you know where I'm starting here, and I'm intending to keep updating you on what I'm doing and how it's coming as I process a long and thorough response to this guy. Currently I am working off of the Gizmodo release of his manifesto; if there's a more complete one, I'll start looking for it tomorrow.
Step one for me, approaching a piece like this, is to sit down and work out what exactly his framework is and pick apart his ideological assumptions. Helpfully, he's laid out an operational definition of what it means for these gender and sex differences right there at the beginning of his screed, so I can start by pointing out flaws in his claims for biological sex differences right there in his initial precepts. I will probably begin the piece by discussing some problems with assuming these traits are 'universal' across human cultures and hunt down/highlight anthropological work complicating that assumption as well as highlighting the fact that the bulk of the psychological research that fuels these studies is done on a very specific population of students who are not in any way globally representative. I intend to then proceed down the list, and I'll be providing my outlines and drafted pieces here as I go so you can see how quickly I'm working. That'll help me organize my thoughts, too.
(Step negative one is, of course, thinking about where to find evidence against and rebuttals of the kinds of thing he's talking about. As a note, I will probably be referencing quite a few secondary sources in this thing, but I will probably start with these three books which remain some of my favorite books on the topic:
Brain Storm: The Flaws in the Science of Sex Differences, Rebecca Jordan-Watson
Testosterone Rex, Cordelia Fine
Delusions of Gender, Cordelia Fine
They're a good starting place as I gear up to tackle this thing. If you want a much wittier and more thorough treatment of these topics than I am likely to produce, I highly recommend all three.)
As I go through this, I intend to outline my thoughts and create a structure of things to respond to. This piece is what I often refer to casually as "fractally wrong," and that's what makes it so overwhelming to tackle: there are so many errors that even if I pretend to accept some of them at face value, his work goes on to yield additional errors. So step two will probably involve making a list of claims he makes and cites that I have either a strong suspicion or outright knowledge from the literature are actually false, plus claims he makes that are just straight up fucking weird.
Heritability, for one thing. If you're not familiar, heritability refers to the amount of phenotypic variance that can be explained by genotypic variance alone: that is, approximately how much of the variation in a population's trait is down to genetic variation underlying that trait? It is usually calculated by taking paired measurements of parents and offspring, averaging each along some scale, and plotting them in a scatter plot and finding the line regression of that data. Calculating that in the context of human sex and gender differences is so odd that I suspect Damore has mistaken "heritability" as meaning something closer to "how much of the trait is controlled by genetics?" which is... not the same thing.
For example, the number of noses on the human face is a trait with extremely low heritability. There isn't a lot of variation in the trait--almost all human faces have only one nose--but there is some, in the form of people who have suffered tragic accidents via plastic surgeon or nose-eating platypus attacks. A few extremely severe cases of cleft palates might also inflate the variability, but even then that is going to produce a cloud of most people without noses (or having two noses!) having one-nosed parents and/or one-nosed children. That will result in almost zero heritability for the trait.
However, the number of noses on the human face is strongly controlled by genetics. Without going in there and cutting off a nose or adding one on, almost every time you gestate a human from human DNA, there's that nose popping up like clockwork. There are very few developmental environments that cause humans to develop with anything other than one nose. So it is not only possible but very likely for a trait with high genetic control to have extremely low heritability, if there is minimal genetic and phenotypic variation in the population around to select on in the first place.
That's the first thing he says that makes me spin my head around and go "what the hell are you trying to say, you incompetent?" but it's unlikely to be the last. So listing his errors as being factually incorrect vs likely misunderstandings of specialist and technical terms in biology isn't a bad way to start this all up.
Thanks again, and while this post will be public so people have an idea of what's going on, I will probably keep further updates private to Patreon donors so as to give those of you who have been able to donate an interesting perk for your investment.