Empathy: diet or exercise?

New Scientist reports on recent research showing that a brain high on empathy functions alot like the brain processing the sound of someone munching an apple:

Our ability to empathise with others seems to depend on the action of "mirror neurons" in the brain, according to a new study.

Mirror neurons, known to exist in humans and in macaque monkeys, activate when an action is observed, and also when it is performed. Now new research reveals that there are mirror neurons in humans that fire when sounds are heard. In other words, if you hear the noise of someone eating an apple, some of the same neurons fire as when you eat the apple yourself.   

That's certainly a new twist on vicarious living. But why settle? Research also demonstrates our ability to grow bigger compassion centers.