밑줄 친 부분이 가리키는 대상이 나머지 넷과 다른 것은?
Most of us probably parent the way we were parented. Louise, a mother who attended my seminars, shared how ① her mother dealt with sibling fighting. Louise said her mother’s infamous threat was always, “If you kids don’t stop fighting, ② I’m going to knock your three heads together!” Louise and her siblings were always puzzled about the specifics of how their mother would actually accomplish such a task, which, thankfully, ③ she never attempted. But what drove her mother to make this empty threat? Extreme annoyance with the sibling arguments, probably. No doubt, Louise’s mother had learned this threatening tactic from ④ her own mother, and, in the absence of any other parenting tools she knew of, she said it to her own children, regardless of whether it worked. If Louise had not learned the effective parenting skills taught in the seminars, ⑤ she would probably be using similarly ineffective threatening techniques with her own children today!
* sibling: 형제(의), 자매(의)