Are you your own best expert? When it comes to your own personality, you should know, right? Maybe not. A study of mine that just came out in this month's Journal of Personality and Social Psychology shows that there are plenty of areas of our personality that we don't know very well, and our friends do.
Where are these "blind spots" in our self-knowledge, and why are they there? My research suggests that while we are the best experts about our thoughts and feelings (e.g., "I tend to be optimistic" or "I often feel anxious"), we're not especially insightful about our actual behavior. People's self-views about their leadership skills or their tendency to dominate group discussions were not any more accurate than the ratings provided by their friends, or even the ratings provided by new acquaintances who had just met them! Everyone's ratings were somewhat accurate, but people themselves had no special insight into their behavior that others couldn't already tell just from meeting them for a few minutes.
What's worse, people's self-views about how intelligent and creative they are were even worse (i.e., less accurate) than their friends' ratings of them. That's right, your friends know better than you whether you're smart and creative. Why is that? I suspect it has to do with how much is at stake for you when you evaluate your own intelligence. It's the same with attractiveness - why can't we just look in a mirror and immediately know how attractive we are? It's because our ego gets in the way. I don't mean that everyone thinks they're beautiful (we all know plenty of people who think they're ugly even though they're not), just that we have trouble being objective when our ego is involved. Some of us might overestimate, others undersestimate, but for most of us things just look fuzzy and unclear. But if we were looking at someone else, we could see things a lot more clearly.