Sometime just before my second child was born, I read that if you stick your tongue out at a newborn, he will do the same. So in young Nicholass first hours, even as my wife was still in the recovery room after 40 hours of labor and a C-section, I tried it. Holding the gooing, alert lad before me in my hands, I stuck my tongue out at him. He immediately returned the gesture, opening his mouth and subtly but distinctly moving his tongue. I hadnt slept in two days. I laughed till I cried.
I did not know it then, but Nick was showing off what some consider one of the greatest drivers of human progress and one of the prime discoveries in recent neuroscience: mirror neurons. These neurons are scattered throughout key parts of our brain--the premotor cortex and centers for language, empathy and pain--and fire not only as we perform a certain action but also when we watch someone else perform that action.