Things you can notice about this chart: first, I really wish Emily Nagoski would have labelled the axes (according to the comments, “You can think of the Y axis as N and the Y axis is desired frequency or frequency of masturbation or whatever other measure of sexual interest you prefer. Left is high interest, right is low interest, and the size of the bubble indicates number of people.”).
Second, it’s totally wrong to say that there are no differences between women as a class and men as a class, in terms of libido. A randomly selected man will probably have a higher libido than a randomly selected woman; a person with extremely high libido is more likely to be male, a person with extremely low libido is more likely to be female. “There are absolutely no differences between men as a class and women as a class!” is something more straw-feminists believe than actual feminists (or maybe I just hang out with awesome feminists), but I would just like to clarify that that is absolutely wrong. Furthermore, this difference has an effect on overall social structures: for instance, the fact that most sex workers cater to men.
Third, the differences? They aren’t huge! There is more than enough space for women who can’t go a day without an orgasm, men who want sex once a year on their birthday, and millions of couples with a horny woman and an uninterested man. Somebody’s gender or sex provides you a little information about their libido, but your confidence interval on “what is Joe’s libido, given no information other than that he’s a cis man” is going to be fucking huge.
Fourth, both a simple essentialist and a simple social constructionist explanation of these differences would be totally inaccurate. Testosterone has known effects on libido: in general, a trans man who begins to take testosterone will find his libido increasing, while a trans woman who begins to take estrogen will find her libido diminishing. There are also more complex changes in sexuality, but those are more likely to differ from trans person to trans person. (See this article for a description of the changes from a trans man.)
On the other hand, social structures also have a huge effect on libido. Women who feel shame about their sexuality or have poor body image. Lack of education about female sexual anatomy. A model of “real sex” that privileges sex that men tend to find pleasurable over sex that women tend to find pleasurable. Porn that overwhelmingly caters to male viewers. Many women’s fear that men they have casual sex with will rapemurder them. Et cetera, et cetera, you’re reading a feminist blog, you can fill in the rest.
I think that most genuine gender differences we find will fit in the same model as libido: they definitely exist and have effects on society, but each group mostly overlaps with each other group, and they generally will be a product of both biology and gender socialization.