Most of the passengers who were on the Titanic drowned when the ship struck an iceberg and sank. However, of those who survived, many went on to live longer than the average person. Perhaps this correlation is explained by something about surviving the Titanic giving them a ‘will to survive’. Can you think of another explanation? (Hint #1: Survivors were not randomly selected. If you’ve seen the movie, you might recall that first class passengers were much more likely to survive – in fact 60% of first class passengers survived, compared with 24% of third class passengers. Does that help?) (Hint #2: First class tickets on the Titanic were very expensive.10 This meant that first class passengers had to be rich. Do rich people live longer or shorter lives than poorer people?)