Imagine that everyone in North America took [a cognitive enhancement pill] before retiring and then woke up the next morning with more memory capacity and processing speed... I believe that there is little likelihood that much would change the next day in terms of human happiness. It is very unlikely that people would be better able to fulfill their wishes and desires the day after taking the pill. In fact, it is quite likely that people would simply go about their usual business - only more efficiently. If given more memory capacity and processing speed, people would, I believe: carry on using the same ineffective medical treatments because of failure to think of alternative causes; keep making the same poor financial decisions because of overconfidence; keep misjudging environmental risks because of vividness; play host to the [tempting bad ideas] of Ponzi and pyramid schemes; [and] be wrongly influenced in their jury decisions by incorrect testimony about probabilities... The only difference would be that they would be able to do all of these things much more quickly!

Keith Stanovich, What Intelligence Tests Miss