Compassion is making a comeback in America

Think back to the United States as it was a year ago, a decade ago, a generation ago. Is the US a more caring or less caring nation now than it was back then?

If you think Americans have lost their compassion, the data would be on your side — until recently. Since the late 1970s, psychologists have measured empathy by asking millions of people how much they agreed with statements such as “I feel tender, concerned feelings for people less fortunate than me.” In 2011, a landmark study led...