 There is yet a further sense in which something might be a social construction. So far we’ve been focusing on social causation: to say that something is socially constructed is to say that it is caused to be a certain way, and the causal process involves social factors, e.g., social forces were largely responsible for my coming to have the idea of a husband, and social forces were largely responsible for there being husbands. But often when theorists argue that something is a social construction the point is not about causation. Rather, the point is to distinguish social kinds from physical kinds. In the case of gender, the point is that gender is not a classification scheme based simply on anatomical or biological differences, but marks social differences between individuals. Gender, as opposed to sex, is not about testicles and ovaries, the penis and the uterus, but about a system of social categories (see, e.g., Haslanger 1993, 2000b; also Wittig 1992; Delphy 1984; MacKinnon 1989).