Like laughter and disease, yawning is contagious. You knew that. But I bet you didn’t know that yawning is actually a sign of empathy. People who yawn a lot are not necessarily more fatigued, they’re actually more able to relate to the feelings of those around them, according to new research. So basically, if you don’t yawn right after you see somebody else yawning, you’re selfish and cold. If you do, you have a heart of gold, or you have really boring friends.