As we look back on history, we've seen many good presidents, many great presidents, and a couple not so great presidents (although everyone's opinion is a little different on who fits into each category). But what's even more shocking is the correlation between the IQ of a president and the predicted quality of leadership. "...one researcher even found that presidents' estimated IQ predicted the quality of leadership among U.S. presidents, with correlations in the .3 to .4 range..." (Psychology textbook p. 333). We know that correlation doesn't necessarily mean causation, but the correlation is at the very least notable. In fact, there may be a relationship between how Americans view the success of a president and that presidents IQ. By taking the estimated presidential IQ from the textbook and the approval ratings of Americans from a Gallup Poll, I found there is a .324 correlation between the two. That correlation is very similar to the quality of leadership that the textbook gives. Once again, correlation may not be causation, but this correlation is notable.
Does this mean we can say that the quality of leadership is related to approval ratings? Chances are it is, but we need the data, and there's always the pesky correlation versus causation hanging over our heads. I'll take my chances on saying they are related based on my own opinions, but that wouldn't be very scientific, would it?