Nearly a year ago, New York made plans to ban the use of electric shocks as a punishment for bad behavior, a therapy used at a Massachusetts school where New York State had long sent some of its most challenging special education students. But state officials trying to limit New York’s association with the school, the Judge Rotenberg Educational Center in Canton, southwest of Boston, and its “aversive therapy” practices have found a large obstacle in their paths: parents of students who are given shocks. “I understand people who don’t know about it think it is cruel,” said Susan Handon...