Dogs try their best to be helpful most of the time. For some dogs, it's easy: they're good at carrying things. They can be helpful. It's awesome. For others, though, acts of service don't come so ...

Mr. Willingham is a psychologist at the University of Virginia and the author, most recently, of “Outsmart Your Brain: Why Learning Is Hard and How You Can Make It Easy.” Picture your preschooler’s ...