After four decades of training and studying dogs, Marjie Alonso has lost track of the number of pets she’s seen because their humans felt they weren’t acting as they “should.” There were the golden retrievers who weren’t “friendly” or “good enough with kids,” and the German shepherds who were more timid scaredy-cats than vigilant guard dogs. There was the Newfoundland (who later turned out not to be a Newfoundland) who had been adopted to fulfill a Peter Pan–esque fantasy of a devoted dog nanny, but acted so aloof that his owners put him on meds …

Alonso, who’s now the executive director of the International Association of Animal Behavior Consultants Foundation, gets it; she really does. Stereotypes about breed “personalities” are hardwired into almost every interaction people have with dogs: They influence which canines are adopted first, which are routed into service jobs, which are allowed to inhabit apartment buildings. Breed is one of the first things people ask about a dog, and the answer has a way of guiding how they’ll treat that animal next. Which is exactly the problem.