Smartest Presidents

I saw an article online which listed the IQ's of each of our presidents. By their own admission, they were doing a bit of guesswork. Since IQ tests weren't developed until about the time of our 26th president, Teddy Roosevelt, there isn't a lot of hard data that can be used. I would think we would take these numbers with a grain of salt. I have some disagreements with a few of these placements and you probably do, too. In spite of that, here we go:

The Top 5 and their estimated IQ scores:

1. John Quincy Adams - 168.8
2. Thomas Jefferson - 153.8
3. John Kennedy - 150.65
4. Bill Clinton - 148.8
5. Woodrow Wilson - 145.1

And the bottom 5:

Andrew Johnson - 125.7
George W. Bush - 124.9
Warren G. Harding - 124.3
James Monroe - 124.1
Ulysses S. Grant - 120.0

We might well ask just how smart these guys really are. Since the mean IQ score is taken to be 100, just like Lake Wobegon, they are all above average. So, President Grant was above average. But was he just a little above or way above?

We could get an idea from looking at how many standard deviations away from the mean he is. Taking the standard deviation for IQ scores to be 16, we see that Grant is 20/16 = 1.25 standard deviations above the mean. Consulting a Z-score table, that puts him in the 89.4 percentile. Pretty good. Even if Ulysses wasn't the sharpest guy ever, it must take a certain amount of intelligence to get elected president twice and to win a war.

What about John Quincy? J.Q. is literally off the chart. Let's go with the runner-up Thomas Jefferson. He is 53.8/16 = 3.36 standard deviations from the mean. This puts him in the upper 99.96 percentile. He's smart. Not John Quincy Adams smart, but smart.

The complete list can be found at http://us-presidents.insidegov.com/stories