Happy 250th birthday: Adam Smith the public figure

Despite the enthusiasm with which it was met in Smith’s time, The Theory of Moral Sentiments gradually slid into relative obscurity. His foundational moral philosophy of society generated no school of followers, let alone a discipline as The Wealth of Nations did. Yet, ironically, remarkably, as the division of intellectual labour splintered the study of man still further, modern neuroscience is confirming Smith’s theory. Just as modern genetics provided the missing biological underpinnings for Charles Darwin’s theory of evolution, so modern neurology is discovering that animals with brains like ours - monkeys and primates - are hardwired for sympathy.

In the 1990s Italian neurophysiologists placed electrodes in monkeys’ brains to study how they co-ordinated their hands and mouth to eat. Having located the small region that fired when an animal lifted food to its mouth, they found that the same region fired - only less strongly - when one monkey simply watched another monkey lift food to its mouth. An extensive network of so called “mirror neurons” was discovered, which fire and enable monkeys to recreate within their own brain what’s going on in the brains of their fellows. Critically, mirror neurons don’t respond in a mechanical way to given physical movements, but only when the observer interprets such movements as having been made with a given intention - for instance eating.

Just as Smith’s Theory of Moral Sentiments had argued that we all share vicariously in the gamut of each others’ emotions, from elation, through to horror and disgust, so recent experiments are now showing that brain regions that activate when we experience pain, disgust, happiness and other emotions also activate when we observe others having similar experiences.

Strange to think that watching an eye slashed open with a cutthroat razor might show us how, for all the self-seeking and bustle of the world, we are nevertheless inextricably bound together by bonds of sympathy.