Those Quizzes On Facebook. How Accurate Are They?

If you use Facebook, then you've probably seen the quizzes. There are dozens of them, and they are popular. You can easily spot them because they have similar titles: "What [blank] are you?" or "Analyze Your [blank]." Invariably, the quizzes collect your personal information, and often that of people you are connected with.

How accurate are these quizzes? Below is a clue, including the results after a user submitted their (unique) profile photo for analysis: