People love things in doubles. Doublemint Gum, Double Stuf Oreos, and Nickelodeon's Double Dare, to name a few. But there's one thing that comes in doubles that people despise, and that's chins. For the testosterone-heavy individual, the answer is simple: grow a beard. For those unable to grow facial hair, here are some simple exercises you can do to turn that double chin into a single.