Deep within the cerebral cortex is a remarkable handful of cells, discovered only recently, called “mirror neurons.” They’re the only known cells that let us intuitively grasp the meaning of other people’s perceived actions and expressions.

As neuroscientist Marco Iacoboni of UCLA explains, they accomplish this by triggering in milder form exactly the same brain activities we’d have if we were doing and feeling the same things ourselves.

This “mirroring,” Iacoboni observes, is a key factor in how we learn by imitation, and, on a social level, why we feel connected.

Other people’s laughter makes us laugh. If they’re sorrowful, our heart is moved. The empathy is automatic, and, when it’s positively directed, that’s good.

Unfortunately, we can also spend time in the company of people who are overly anxious, resentful, complaining, or downright angry. When you notice negative feelings like these washing over you, ask yourself: are they coming from a legitimate source within me? Or are they perhaps being picked up from others?

If you can conclude that there’s really no good reason in your own immediate personal life to be having them, you may very well find that they diminish.