One of my Engkish teachers back at school was an odd bloke. Amongst his many opinions was that it was the duty of intelligent middle class boys such as myself to go out and spread our seed. Likewise it was the duty of good intelligent middle class girls to have the resulting children and stay at home to look after them. This, you see, was because the world was becoming dumber as intelligent people used contraception and had fewer children and stupid people bred like bunnies.

A study commissioned for the Scottish parliament has reached a similar (though couched in slightly- just- more PC language) conclusion.