Cities both celebrate and erase difference. Cities are inclusive. They transcend the individual. And in so doing, they make all those strangers part of ourselves, of our own identity, our own self-category. And so we give blood, or open our homes, or race to get the wounded to the hospital. We aren’t being selfless. We are merely extending the concept of self in a way that the city makes natural. In moments of tragedy, we refuse both isolation and chaos. Instead, we put our identity as city dwellers—in this case, as Bostonians—first, and draw strength from a shared sense of self that we may not even have guessed existed.
Maria Konnikova is the author of “Mastermind: How to Think Like Sherlock Holmes” and writes the Literally Psyched blog for Scientific American.