Women donate more than men. They are more likely to give, and they give more money. So why is the smart giving/effective philanthropy/whatever-you-want-to-call-it movement so skewed male?
About a quarter of the members of Giving What We Can and 80,000 Hours are women. At any kind of discussion on efficient giving, I'm usually either the only woman or one of two women there. This doesn't bother me in itself, but it means we're missing people who could have a lot to give to the conversation. I don't believe women are more selfish than men or that they want to help people less than men do. So where are they?
Some of my guesses:
A lot of this movement came out of university philosophy departments. At least in the US, only 1/3 of philosophy PhD students are female - that's more skewed than math or almost any of the sciences. Apparently not that many women want to sign up for five years of having their ideas ripped apart.
There's a good bit of finance and math involved in finding the best charities. I have very little math background, and while I think posts like this are very important, I can't get through them. A lot of women also didn't do much with math or economics. Until recently, there was never anything I wanted to understand that required me to know much about math or money, and I was disheartened to realize I was going to have to learn some.
Lately, there's also an increased emphasis in this movement on careers and choosing a career that will let you do the most good (usually through high pay). I think boys get the message early on that they should optimize for high pay because this is what will impress other men, attract mates, and support their families. As a girl, I never got the message that I needed money to do these things. The emphasis was more on personality, beauty, and accommodating other people. Unfortunately, these things are not especially helpful to me now in reducing child mortality.
As a child I, at least, was told that my interest in helping strangers was somehow unnatural if it wasn't preceded by being extra nice to people around me. Ordinary childhood squabbles with my sister often brought on the question from my mother, “How can you care so much about strangers and so little about your family?” I think I was about as selfish in my everyday activities as other children and teenagers I knew, but to this day if I hurt someone's feelings I get the hypocrisy accusation from my mother. If I were a boy, I'm not sure if this would have happened. I think there's less pressure on boys to make nice, and it's considered more normal for them to care about the big picture more than household emotional politics. Girls get stronger approval if they focus their energy on being nice to those near them.
(To be fair, my parents also tell me they're proud of my giving. But they seem to regard writing a check and refraining from snarky comments as the same skill, and in fact I'm better at the former than the latter. Working on it, though.)
In adulthood, women are still primarily responsible for the emotional wellbeing of the household. In most families I know, the mother is more financially permissive with the children than the father is. Women understand that they will be in charge of distributing family money and time to keep everyone happy. It may be emotionally harder for them to not buy the kids all 17 of the Christmas presents they asked for, or to decide to have fewer kids in the first place, or to work long hours and serve frozen dinners. A man who chooses not to have children, or to raise his children on a voluntarily low budget, probably won't get the same flak a woman would. So the choice to give more may be harder for women.
Non-efficient charity (the food drive, the house of worship, the Girl Scout cookies, the solicitations from the children's hospital and the animal shelter, the cousin who needs a loan) is largely about community connections. Women are often in charge of maintaining these connections on behalf of a family. I think this is why you see higher donations from women. It's true of woman-headed households and not just women acting on behalf of a joint household, but I expect that's because we continue in the patterns we were socialized to even if our later home life doesn't match the conditions we were expecting.
My message to my female readers (there are some? Right?) is: you can do this. You can have a happy family life. You can be analytical and argumentative. You can learn statistics. You can do what you know is the right thing rather than what will make you seem most normal.
Your mother might be annoyed with you, but that's pretty much inevitable.