Social Psychologists
There are two types of people in this world, introverts, and extroverts. Obviously one can not strictly categorize people into one of these two categories, but it is safe to say that more often than not people do tend to have stronger tendencies towards one personality type than the other.
But who knew introverts were more likely to be able to categorize someone’s personality without any formal training? I guess it makes sense considering they probably spend a lot more time observing and watching other people’s behaviors as opposed to acting them.