Some things are self-demonstrating

My mom (a formidable woman with a doctorate in education, whom I contradict with care) firmly believes that sex roles are learned responses, not innate. But she's not in my living room at the moment, to see 1-year-old Mona carrying on an involved conversation with a stuffed elephant, while 3-year-old Dai (short for David) is "fixing" the vacuum cleaner by pounding on it with a plastic hammer. Some things you just don't have to argue.