There’s no easy way to rate dog intelligence. As psychologist Stanley Coren wrote back in the 90s, there’s adaptive intelligence (i.e., figuring stuff out), working intelligence (i.e., following orders), and instinctive intelligence (i.e., innate talent) — not to mention spatial intelligence, kinesthetic intelligence, interpersonal intelligence, and more. Indeed, as animal behaviorist Frans de Waal has argued, humans tend to judge animal intelligence in limited and unfair terms and often bungle the experiment. While labs at Yale, Duke, and around the world are studying this question, for now we do at least have data on one metric: working intelligence. Coren, in...