Fourteen years ago neuroscientists introduced the world to a captivating new idea about the way our brains might work: they discovered the existence of specialized brain cells in the brains of macaque monkeys that are activated both when a monkey performs an intentional action (e.g. grabbing a banana) and when it sees another monkey performing that same action. They called these special brain cells mirror neurons since the monkeys mirrored in their own minds the actions of their neighbors. Scientists learned that at the brain level, monkey see was not so different from monkey do.

Even before researchers confirmed the existence of similar mirror neurons in human brains, which they did in 2007, the idea had worked its way into the zeitgeist and become a potent new way of seeing ourselves in relationship with each other. People have begun to wonder if mirror neurons could be responsible for language, culture, empathy and even morality. Where Darwinian survival of the fittest has heretofore imagined us as the strong pitted against the weak in a fatal struggle for food and sex, the mirror neuron suggests the importance of social strengths: that we are hardwired for empathy, that we are naturally interested not only in our own needs but also in the interests of others. As noted philosopher A.C. Grayling has said: “The essential point is that mirror neurons underwrite the ability to recognize what helps or distresses others, what they suffer and enjoy, what they need and what harms them.”

—Andrew Tuplin