Although girls disclose to friends about problems more than boys, little is known about processes underlying this sex difference. Four studies (Ns=526, 567, 769, 154) tested whether middle childhood to mid-adolescent girls and boys (ranging from 8 to 17 years old) differ in how they expect that talking about problems would make them feel. Girls endorsed positive expectations (e.g., expecting to feel cared for, understood) more strongly than boys. Despite common perceptions, boys did not endorse negative expectations such as feeling embarrassed or worried about being made fun of more than girls. Instead, boys were more likely than girls to expect to feel "weird" and like they were wasting time. Sex differences in outcome expectations did help to account for girls' greater disclosure to friends. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.