Here’s a simple arithmetic question: A bat and ball cost a dollar and ten cents. The bat costs a dollar more than the ball. How much does the ball cost?

The vast majority of people respond quickly and confidently, insisting the ball costs ten cents. This answer is both obvious and wrong. (The correct answer is five cents for the ball and a dollar and five cents for the bat.)

When people face an uncertain situation, they don’t carefully evaluate the information or look up relevant statistics. Instead, their decisions depend on a long list of mental shortcuts, which often lead them to make foolish decisions. These shortcuts aren’t a faster way of doing the math; they’re a way of skipping the math altogether. Asked about the bat and the ball, we forget our arithmetic lessons and instead default to the answer that requires the least mental effort.

I don't think this demonstrates that smart people are stupid. I think it demonstrates that some people can be fooled by 'trick' questions, but I'd say that the test of whether someone is smart might be how easily or often they can see past the trick.

I got 'em both right.

I got that question wrong, but the lily pond one right. Not sure what that says about me.

http://www.newyorker.com/online/blogs/f ... udies.html

I got that one and the lilypad with no problem. My first thought in both cases was the obvious wrong answer, but it was immediately followed up with no, that's not right. It would have been interesting to try this without knowing the context of the questions.