This is an edition of The Wonder Reader, a newsletter in which our editors recommend a set of stories to spark your curiosity and fill you with delight. Sign up here to get it every Saturday morning. My colleague Derek Thompson has written about Americans’ social isolation and anxiety. But this week, he writes, “I thought I’d turn things around for a change. What matters most for happiness—marriage, money, or something else entirely?” Reading about the key to happiness can sometimes feel like a trick: Could it really be as simple as a given expert makes it out to be? As Derek notes, “Clever sociologists will always find new ways of ‘calculating’ that marriage matters most, or social fitness explains all, or income is paramount.” But his research leads him to what he calls a “subtler truth”—a “happiness trinity” of which “finances, family, and social fitness are three prongs” rising together and falling together. Today’s newsletter explores some subtler truths about American happiness. On Happiness The Happiness Trinity By Derek Thompson Why it’s so hard …