Jane’s teen daughter has never been particularly difficult. This summer, though — the last one before she heads off to college in the fall — has been another story. “She’s adverse to being at home, she stays out till midnight no matter what’s happening, and she makes it clear she doesn’t like living here and can’t wait to get out of here,” says Jane (not her real name) about her suddenly taciturn kid. “She’s not really participating in the family unit anymore, since we’re all ridiculous. She’s got bigger and better things to do.” Her kid has gotten so unpleasant...