You watch a short video about one puppy needing food and feel really sad. You donate some money. But then you see a clip about hundreds of puppies in need—and suddenly, you feel less moved and donate less. Or you hear about one lonely elderly neighbor who needs a friend and you offer to visit. But if you heard about dozens of elderly people needing help, you might think, “Someone else will do it,” and not visit at all. Take the quiz to find out what’s really going on here.