There is a huge difference between what people actually know and how much they think they know.”

                 –Nassim Taleb

In his book, Super Crunchers: Why Thinking-By-Numbers is the New Way to Be Smart, Ian Ayres writes, “People think they know more than they actually know.” To prove this point, he asks his readers to answer 10 questions so that they are 90 percent confident that their answer is correct. For example, in the first question, you are to fill in the blanks: “I am 90 percent confident the length of the Nile River is between ___ miles and ___ miles long.”

                                                                                                                                 Low                 High

  1. What is the length of the Nile River, in miles?                        _____              _____
  2. What was Martin Luther King Jr.’s age at death?                  _____              _____
  3. How many countries belong to OPEC?                                      _____              _____
  4. How many books are there in the Old Testament?               _____              _____
  5. What is the diameter of the moon, in miles?                           _____              _____
  6. What is the weight of an empty Boeing 747, in pounds?   _____              _____
  7. In what year was Mozart born?                                                    _____              _____
  8. What is the gestation of an Asian elephant, in days?           _____              _____
  9. What is the air distance from London to Tokyo, in miles? _____             _____
  10. What is the deepest known point in the ocean, in feet?     _____              _____

The answers are listed below. Did you get at least 9 answers correct? If not, don’t worry, you’re not alone. Most people get more than one answer wrong because they are over-confident. Or, as Nassim Taleb says, “There is a huge difference between what people actually know and how much they think they know.”

More often than not we know less than we think we know. This finding should lead all of us to have some intellectual humility.

Answers: (1) 4,187 miles. (2) 39 years. (3) 13 countries. (4) 39 books. (5) 2,160 miles. (6) 390,000 pounds. (7) 1756. (8) 645. (9) 5.959 miles. (10) 36, 198 feet.