girls than for boys—a fact that is likely to affect social interactions between males and females of the same age, particularly during the early years of adolescence. In addition, pubertal changes begin about 15 months earlier in black females than in white females (Herman-Giddens et al., 1997; National Research Council and Institute of Medicine, 1999a). As a result, anyone working with 6th graders will immediately notice major differences in the physical maturity between girls and boys, as well as among groups of girls. Many females at this age look and act like fully mature young women. In contrast, most of the males still look and act like boys. The impact of these differences on the development of early adolescents is likely to vary by cultural group, depending on beliefs and norms about appropriate roles for physically mature individuals, appropriate sexual activities, and ideals related to female and male beauty. Such differences also have implications for the design of developmentally appropriate experiences for early adolescent girls and boys of different racial or ethnic groups in community programs. Girls will need educational programs related to puberty and fertility change earlier than boys. Girls are also likely to need places in which to discuss family interactions and concerns about their changing bodies at a younger age than boys are, and black girls are likely to need these experiences at a younger age than white girls.
There are also major individual differences in the timing of puberty within each sex and racial/ethnic group—some children begin their pubertal changes earlier than others (Stattin and Magnusson, 1990). The timing of pubertal development has major implications for many aspects of life. Once again, cultural beliefs and norms are likely to influence the meaning of early maturation for both girls and boys, so the implications of pubertal timing for youth programming will differ across groups. For example, among white populations, early maturation tends to be advantageous for boys, particularly with respect to their participation in sports activities and social standing in school. In contrast, early maturation is often problematic for white girls—being linked to increased rates of eating disorders, depression, and involvement in a variety of problematic behaviors (Caspi and Moffitt, 1991; Flannery et al., 1993; Ge X et al., 1996b; Graber and Brooks-Gunn, in press; Silbereisen et al., 1989; Simmons and Blyth, 1987; Stattin and Magnusson, 1990). Interestingly, these problematic correlates of early puberty are not as evident in black populations (Michaels and Eccles, 2001; Simmons and Blyth, 1987). We do not know about the strength of association for other racial/ethnic groups. Although we do not yet understand the origins of these ethnic