When I tell people about my PhD—that I research ways to make technology more engaging for women—I usually brace myself for a reply like this: “Why would you bother to do that? Everyone knows men are just better with technology. It’s science!”. It happens more often than you would think, and more often than I’d like. And then I get into a whole conversation about why this isn’t true. So I thought I’d lay out the arguments against biological determinism—the idea that ‘male’ and ‘female’ bodies are in some way built to have different competencies in doing maths, designing bridges or operating computers—so I can point people here instead. And then there turned out to be a lot of arguments to cover and this turned into a pretty long read.