Cambridge has a superfluity of these. One theory to explain this phenomenon is that all these geeks work so hard at school that they don't have time/energy/social skills for a sex life/ relationships. Then, because they've worked so hard, they get to Cambridge, and the pressures which repressed their normal social development are lifted, and they are free to start experimenting. Except the sex ratios are badly skewed and the majority of available individuals are ... other male geeks in precisely the same situation.