Many of these [biological] differences are small and
there’s significant overlap between men and women, so
you can’t say anything about an individual given these
population level distributions.
That would imply that there will be women at Google who are more inclined towards software engineering than some of the men.
As a measure of how easily talk of averages degenerates into talk of individuals, let me point out that the comment you're replying to is talking about averages and you are talking about individuals. Your response to "hey this memo is talking more specifically about women at Google being less suited to tech on average" is to say "well I mean there are these weasel words about individuals standing out so I don't see how Damore could be talking about women at Google on average" -- I mean, no, that's exactly what Damore is talking about, averages.
You ask "Where did he say that?" and I'd be surprised if there's any one succinct place -- it's one of the two main topics of the whole memo, and the memo does not have a coherent topic sentence or even really a coherent argument, so I think it's likely absent.
But, like, Damore makes a case to the effect that "biological explanations can't be ruled out" and then reverses those weasel-words by suggesting that his biological explanations be used to guide policy by, say, encouraging pair programming which he supposes to be something that women are likely better at on average. This sort of move suggests that he thinks the biological effects that he's citing (see note [1]) are big enough to guide policy, which they're not. You don't need to take my word for it -- the main author of the article Damore is citing was asked to read Damore's memo and this is his take on it [2].
Of course the problem is even worse in that this article which Damore used to write his article is psychological; it is based on doing a personality test in a bunch of different nations. That makes it very hard to conclude anything biological about it, so every time that Damore mentions "biology" in his memo, that is an interpretation of his own devising. The original personality-study article also interprets its findings biologically but it is really tenuous [3]. In fact neuroscientists have also been studying the brain and they have not found a clear biological difference between male and female brains [4].
[1] He gives a summary of a Wikipedia summary of an article by Schmitt et al. (2008). The PDF is freely available by the university at http://www.bradley.edu/dotAsset/165918.pdf but the sample sizes were I believe later corrected as an erratum, so I am not sure which one this has.
[2] Schmitt, evaluating later research as well, summarizes by saying that sex differences are only "accounting for less than 10% of the variance" and that using this to guide policy is "like operating with an axe. Not precise enough to do much good, probably will cause a lot of harm," in an article at http://quillette.com/2017/08/07/google-memo-four-scientists-... .
[3] The argument in the article involves their surprise that the majority of the discovered effect apparently disappeared in Africa and East Asia. Their interpretation is literally that those cultures are so much less economically developed than we in the West are, that their women must feel so much less free to just be themselves, and therefore they act more like men as a sort of baseline survival tactic. Read the paper; it's a very 'you cannot possibly be saying what I think you're saying, can you?' type of experience.
But, like, Damore makes a case to the effect that
"biological explanations can't be ruled out" and
then reverses those weasel-words by suggesting that
his biological explanations be used to guide policy by,
say, encouraging pair programming which he supposes to
be something that women are likely better at on average.
But the very fact he made that suggestion implies that he also wants to narrow the gender divide. By your logic, if he wanted to reduce the number of women in tech, he'd be advocating less pair-programming.
It also seems to me that the pair-programming idea was plucked out of the air to be used as an example to further a discussion, not a solution to be implemented.
This sort of move suggests that he thinks the biological
effects that he's citing (see note [1]) are big enough
to guide policy, which they're not
I'm inclined to agree with that. But his memo was written in response to policies that are already being implemented, which he thinks are bad.
I'm really not concerned about whether his ideas are good or bad - the experts on this subject can work that out between themselves. What concerns me is that, while he was confident enough in his theory to put it forward for wider scrutiny, the makers of the policies he is objecting to weren't. And when they were presented with a counter-argument anyway, they had to set an example to everyone else who might wish to speak up by having its author fired and smeared with accusations of bigotry.
