He made an argument for his conclusion based on his evidence. You can't prove with science that those things are why women prefer those jobs. But if the facts he cites in his evidence are true, it would not be unreasonable to hypothesize that women may prefer those jobs. If you want to argue that point, I think it's totally debatable. But that's just it - it's debatable.
EDIT: And as has come out, the author of this memo has a PhD in Biology. Here are comments from four PhD scientists in Sociology on the issue, if you'd like some credentials to go with it:
Did you read what those scientists say? While there is consensus on the memo's statements about biological differences (which again - I agree with), there is hardly consensus on the conclusions drawn:
"But it is not clear to me how such sex differences are relevant to the Google workplace. And even if sex differences in negative emotionality were relevant to occupational performance (e.g., not being able to handle stressful assignments), the size of these negative emotion sex differences is not very large (typically, ranging between “small” to “moderate” in statistical effect size terminology; accounting for less than 10% of the variance). So, using someone’s biological sex to essentialize an entire group of people’s personality would be like operating with an axe. Not precise enough to do much good, probably will cause a lot of harm."
He doesn't use it to essentialize each individual. He's pretty explicit about that, if you read his memo. He's clear about the fact many women are exceptions to these patterns, just as are many men. The point he's making is that, perhaps, in aggregate, these differences explain the relative proportion of women in technical jobs. He isn't saying women shouldn't do technical work. He's not saying Google shouldn't hire women. He's not even saying that the women working at Google don't deserve their jobs, or aren't good at them. Far from it. What he's saying is that efforts to actively recruit women in tech, in an attempt to achieve gender parity may be misguided, because part of the reason for the proportionality difference may be biological. That's the essential point he makes, and whether or not you agree, I think its fairly clear that his point is at least not crazy and worthy of firing.
Actually, you can absolutely use social science methods to attempt to demonstrate (or in this case, disprove) these kinds of links. But let's put that aside for a moment, and discuss what is objectionable about the memo.
What are the costs/benefits of having this "debate" at work over a hypothesis that cannot be proven, as you state?
Look again at what the author was doing. He was using scientifically demonstrated biological and psychological differences between men and women (women have "higher agreeableness") to hypothesize about how that affects their work choices and, notably, their performance ("This leads to women generally having a harder time ... speaking up, and leading.").
What this is doing is connecting a gender stereotype (which, sure, is scientifically supported in aggregate - that's true for a lot of stereotypes!) to work practices and outcomes. The authors claimed benefits of presuming that this connection is true are basically a) this will make conservatives feel more accepted at work, and b) diversity is "bad for business" (which is just provably wrong by an enormous amount of evidence that the author ignores). I think a) is absolutely a worthy benefit, but there are lots of other ways to do this without linking gender stereotypes to work performance!
Now let's look at the harms of having this "debate", particularly at work, which are numerous and measurable. While there are no studies demonstrating the link between biology and STEM job performance, there are many studies demonstrating the impact of widespread gender bias in STEM fields (classic recent reference: http://www.pnas.org/content/109/41/16474.abstract) and how it affects hiring and advancement. The memo's author correctly acknowledges these types of biases. So the harm is perpetuating gender biases in the workplace that affects people's careers. Not to mention the harms of opening up Google to gender discrimination lawsuits (ala https://en.wikipedia.org/wiki/Price_Waterhouse_v._Hopkins), the productivity cost of employees who don't want to work with people with publicly broadcasted unproven gender biases that could affect their decision making ("hostile work environment"), etc. And not to mention losing the many economic benefits that a company reaps with a diverse, inclusive workplace.
So no, I don't think it's worth having this "debate", especially at work, where the benefits are negligible at best, and the harms are clear. If you want to have this debate, go write a medium article or something. Don't send this around your workplace. It's not that hard, really. People call this thought policing, or groupthink or whatever, but it's just harmful and a waste of time at work.
Even if there is bias, in what position is Google to fix it? Unconscious bias retraining does not work.
If bias exists it is culturally and biologically motivated and that can only be fixed by changing the culture significantly.
Women in free cultures do not like STEM. That is a fact. In countries where gender roles are being silenced (that's a good thing) women dislike STEM even more!
I went to a STEM focused high-school that had equal numbers of women and men (3000 students). Not the same percentage went for STEM fields after graduation. Women were also more successful during high-school. Every year the questionnaire confirms that women just aren't interested in STEM and go to fields that deal with people much more (medicine and similar social fields - rehabilitation, working with children with disabilities, social work etc.))
Show me a study that measures gender bias, does an educational intervention and succeeds in improving that measure significantly. None exist. At best they do not work.
> I'll let you do the homework finding citations about how you're wrong here.
Cool, good thing I did my homework. I'm quite aware that percentage of women in STEM is increasing every year. Check out research for countries that have successfully removed gender roles.
> Nice anecdote! Is there anything else about high school that you'd like to generalize to the entire population of the world?
Good thing that there's research confirming the same thing. Although I was not generalizing. The 3000 students and the results of questionnaire every year are pretty consistent. I'm sure someone will do a study on the data, will link to it surely when it happens. Although, I'm sure it will not matter given that you value meta-analysis but only those that confirm your bias.
EDIT: And as has come out, the author of this memo has a PhD in Biology. Here are comments from four PhD scientists in Sociology on the issue, if you'd like some credentials to go with it:
http://quillette.com/2017/08/07/google-memo-four-scientists-...