Neuroscientist, Tania Singer and her team recruited volunteers to play a game. Some were asked to play by the rules. Others were instructed to ignore them. To not play fair.

After all participants played the game together, they were then asked to observe each other in a second activity. Scientists measured some of the volunteers' brain activity as they observed some of their former game opponents apparently being subjected to different levels of pain. Result?

The brain areas that signal pain became active in all who thought they were observing pain in others. This provides neural evidence of their empathy.

Yet, when those who'd played "unfairly" in the earlier game appeared to be in pain, male volunteers who observed them showed significantly less empathetic brain activity than when they saw fair-players in apparent pain. In fact men felt more desire for revenge.

For women the response was different. They showed the brain responses of empathy regardless of how they felt about the participants' moral behavior. Earlier research supports this finding.

Regrettably, I feel I'd respond more like a man in this experiment.

Learn more about how our brain affects our behavior in Donald Pfaff's book, The Neuroscience of Fair Play. Relatedly read On Being Certain and Predictably Irrational.

Here's the good news. Men and women can use meditation to change our instinctively negative reactions - even in the face of unfair or otherwise negative behavior. Monitoring the brains of Tibetan monks at the University of Wisconsin-Madison, neuroscience professor Richard Davidson found that the monk' first instinct was compassion rather than anger.

Here's the bad news, at least for many of us.

To become that compassionate, monks spent at least 10,000 hours in meditation. Learn more about the power of compassion in Emotional Awareness, a book by the foremost expert on reading faces and on lying, Paul Ekman.