"A rich kid is much more likely to leave an impact on the world and this is what these schools want. I once (10 years ago?) read an article about exactly this. The comparison were some US elite high school that strictly select on IQ and alumni were much less successful than expected (yet, more happy in live). George W went to Yale as far as I remember. I doubt that he scored super high in any IQ test. But he was undoubtedly very successful in live. "

That's the self fulfilling prophecy that modern democracies are/should be trying to avoid. Otherwise we are on the track of building up a new aristocracy where only the rich and powerful get the opportunity of making a difference.