The probability that you, who are reading this, having taken a Facebook quiz is very close to 100%. I'm sure there are a few readers who have never taken a Facebook quiz, but if you're like me, you've been suckered in to taking one or a hundred. Is there any science behind these quizzes? No. They're fun to take and it's fun to see what the results are, but the results, other than the fun behind them, are meaningless. Anyone with the time and desire can put together a quiz, however, there's no science in the actual results.
Think about some of the quizzes you've taken. Which Disney princess are you most like? Someone can ask a few questions to test your personality and have those linked to the personality of Disney characters. There may be a bit of truth in these quizzes, but unless there are many, many questions asked, you may only loosely have a personality similar to a Disney character.
Other quizzes have no truth to them at all. Consider quizzes that don't ask you questions, but supposedly scan your Facebook feed to obtain the information it needs to supposedly arrive at a result. Is the quiz really scanning your Facebook feed and using your posts to determine results? Likely not. How do you know? Refresh your browser and take the quiz again. Do you get the same result? If not, guess what, the quiz is simply returning a random answer.
Don't get me wrong, Facebook quizzes can be fun and entertaining. Most people realize there's little science behind them and take nothing away from the quiz. If this is you, fantastic, keeping quizzing away. However, if you take these quizzes as absolute truth and let them run your life, that's a problem. It may sound crazy that someone does this, but consider the number of people who are firm believers in astrology. Consider those you know who read their horoscope everyday and honestly believe it is a scientific, truthful report of your day/week/month.
I like Facebook quizzes, but there is always the possibility of unintended harm and unintended anti-science.