Imagine that you're sitting by yourself in the park. As you're happily soaking up the autumn weather, you discover a dark blue minivan with stick figure family car window stickers: one dad, one mom, three kids, and a small cat. A guy sitting next to you on the wooden bench suddenly turns to you and says, "Did you know that families that have those family window stickers also have happier kids than families without them?" One of your eyebrows perks up as soon as you hear his w