The noted psychologist, Doreen Kimura, has argued that we should not expect to find equal numbers of men and women in various professions because there is a natural sexual inequality of intellect. In rebuttal I argue that each of these mutually supporting theses is insufficiently supported by the evidence to be accepted. The social and ethical dimensions of Kimura's work, and of the scientific study of the nature-nurture controversy in general, are briefly discussed.