While I am a New York family law attorney, I can tell you that the answer to your question is a universal one: Since every child matures at a different rate, and the ability to be self-reliant and responsible varies among children of the same chronological age, the decision whether to leave an 11-year-old alone at home will be an individual one for every set of parents, who can more accurately gauge the responsibility and self-reliance of their own children better than anyone else.