SALT LAKE CITY - Meanness in girls can start when they still are toddlers, a Brigham Young University study found. It found that girls as young as 3 or 4 will use manipulation and peer pressure to get what they want. "It could range from leaving someone out to telling their friends not to play with someone to saying, 'I'm not going to invite you to my birthday party,'" said Craig Hart, study co-author and professor of marriage, family and human development at BYU. "Some kids are really adept at being mean and nasty." They regularly exclude others and threaten...