Rationality is highly correlated intelligence

According to research K.E. Stanovich, this is not the case:

Intelligence tests measure important things, but they do not assess the extent of rational thought. This might not be such a grave omission if intelligence were a strong predictor of rational thinking. But my research group found just the opposite: it is a mild predictor at best, and some rational thinking skills are totally dissociated from intelligence.

See http://www.project-syndicate.org/commentary/stanovich1