Brain-Teasers during interviews

Hunter Walk (Product Management, YouTube) has a couple of great posts on Product Management.
He links to this post by Ken Norton (now at Google) on hiring PMs. The post is pretty great, but I had doubts about one point.

"I usually ask an interview candidate a series of logic questions to gauge intelligence. "

I've had quite a few interviews where you spend some time on logic questions/brain teaser-type thingies, and have developed doubts about the effectiveness of this.

There are two reasons for this:

• quick on your feet is great, but not if you're going to get up and start running in the wrong direction!! I've been lucky enough to get to hang around a lot of smart people (often at a respectable distance:)). I've also been around a lot of people that sounded smart. There is a difference, and I think "quick on their feet" favors that latter. It favors confidence and polish, over thoughtfullness and thoroughness. It favors quick frameworks over original approaches and explorations that may not work. Also, as the rest of the referenced post covers, there are a lot of things that matter and you almost never want to hire just based on IQ, because that's rarely going to be the differentiator. Drive, the right attitude and a willingess to take risks, continually refine/iterate and learn from others is almost always more desirable. I'd try to use the interview to get a better sense of that, rather than guess at attributes that the results of standardized tests have a decent shot at predicting....and that are already on the resume!
  
• the second reason I think it's a bad idea is that quite frankly, its pretty game-able if you try to scale it. Asking good brain-teasers/logic questions is not trivial and being able to understand the approach taken by a candidate if its not the conventional one isn't easy. I've had one interview that was a disaster because the interviewer absolutely refused to believe there was another approach to another problem. I've also had another interview cut short because I said, "Um. actually I know this one." and the interviewer was stumped after that.:) This doesn't apply just to brain teasers. Interviewing out of college, I've lost count how many times I was asked to reverse a linked-list. The universe of logic problems is not infinite and if an interviewer is forced to ask them, it shrinks radically and quickly.
  

To quote Dennis Miller, "Of course, that's just my opinion anyway. I could be wrong!" :)