Mrs Gross said she believed that girls knew when they were being mean to each other, but added: “I don’t think they know quite how much it hurts, because the people who may be doing it, it may not happen to them.’’ Research suggests that girls are less confident when it comes to speaking out and saying “no” to their friends, Mrs Gross said. “Hence, this is why they’re so vulnerable to exclusion and inclusion … they’re much more conforming, more subject to peer pressure than boys are.’’