I have developed a fool-proof way of determining rather or not someone is smart. It's super-easy. Just watch their eyes. The smarter a person is, the more their eyes will move around in general. This is an indication of thinking.
Birds who have clearly been touched by an angel, however, will have eyes that don't move much. They rarely even blink. This is because there isn't a whole lot of cognition going on. Mall's open, nobody's shopping. Light's on, nobody's home. Sun's up, nobody's outside. You get my drift.
Try it. You'll be amazed at the accuracy.