Research has shown that sibling relationships may influence adolescent intimacy skills. Depending on the quality of the relationship, siblings can serve as a stepping stone for their brothers and sisters into the peer social world. In a cross-sectional study of 386 13- to 20-year-olds, Bigelow, Tesson, and Lewko (1999) found that when an adolescent has a sibling who is relatively close in age, their typically peer-like interaction style aids the development of social rule usage with peers, friends, and dating partners. Adolescents with siblings are more likely to use rules of compliance and social facilitation, to exhibit loyalty, and to use information management with close friends; they are more likely to use rules of compliance, to exhibit loyalty, and to engage in the management of feelings with dating partners. In short, an adolescent's sibling serves as a testing ground in which the rules of interaction largely mirror the rules of peer, friendship, and romantic relationships. With a sibling, adolescents have the opportunity to practice and hone their social skills. In light of these benefits, it is excellent news that intimacy-related activities with a sibling (i.e., telling each other about a bad day; sharing private things) has recently been found to increase with age (Cole & Kerns, 2001). The study was cross-sectional in design, and based on a sample of 170 primarily white fourth-, sixth-, and eighth-graders.