Do Humans Alone 'Feel Your Pain'?

Once upon a time, the United States had a president known for a peculiar facial display. In an act of controlled emotion, he would bite his lower lip and tell his audience: "I feel your pain." Whether the display was sincere is not the issue here; being affected by another's predicament is. Empathy is second nature to us, so much so that anyone devoid of it strikes us as dangerous or mentally ill.

At the movies, we can't help but get inside the skin of the characters on the screen. We