“As far as we can tell, we’re the only species that regularly engages in counterfactual thinking,” writes preschool teacher Tom Hobson, describing an argument he witnessed between two students over whether they should pretend to be tiger babies or polar bear babies. This kind of dramatic play is really important to kids—it teaches them to understand other people’s perspectives, for one thing—and it’s so important that they will argue over the “truth” of things that they know are objectively not true. That bickering has real value, Hobson notes. It’s a sign of healthy social and emotional development, helping children learn how to compromise and figure out a way to keep playing without letting their imaginative differences stand in the way. “It’s easy to dismiss children’s dramatic play as silly, as a waste of time even, especially when we hear them intensely bickering over ‘truth,’ but what they’re doing is exercising their imagination and creativity,” writes Hobson. As adults, we o...