If you've ever doubted your intelligence, or any other perceivable trait, you might want to get a second opinion. According to Scientific American, your friends may be more realistic judges of how smart you are (among other things).
A 2010 study found that friends are significantly more accurate in judging traits like intelligence, talkativeness and creativity-traits that are observable and measurable. So when a friend says, "You know, you're really smart," it's very possible that you really are smart. What we can accurately gauge is our own levels of anxiety and self-esteem. So when giving a presentation, for instance, you're probably much more aware of state of mind than your audience is. And speaking as a presenter, that's a good thing to keep in mind
Next time you're feeling dumb or uncreative, it might be worth reminding yourself that you're not necessarily right. Check with your friends. They might be a better authority on the matter.
Know Thyself [Scientific American]