Delilah has a hypothesis that happiness increases people’s tendency to help others. To test this, she creates an experiment where she has some people watch a sad movie and other people watch a happy movie. After watching the movie, she asks them to donate money to a charity and measures the amount of money they give. Suppose delilah re-ran her experiment but instead of measuring the amount of money people donated to charity, she asked them whether or not they would be willing to volunteer at a soup kitchen. Delilah would be changing?.
