Adolescence

As a result of the activation of the hormones controlling pubertal development, early adolescents undergo a growth spurt, develop primary and secondary sex characteristics, become fertile, and experience increased sexual drive. There is also some evidence that the hormonal changes are linked to behaviors such as aggression, sexuality, and mood swings. These relations are quite weak, however, and are often overridden by social experiences.

In general, pubertal changes begin twelve to eighteen months earlier for girls than for boys. As a result, anyone working with youth in grade six will immediately notice a major difference in the physical maturity between girls and boys. Many girls at this age look and act like fully mature young women, while most of the males still look and act like boys. The impact of these differences on the development of young men and women will vary by cultural group depending on cultural beliefs and norms, such as appropriate roles for physically mature individuals, appropriate heterosexual activities, and ideals related to female and male beauty.

There are also major individual differences in pubertal development within each sex. Some children begin their pubertal changes earlier than others. The impact of these differences depends on the cultural beliefs and norms that relate to the meaning of early maturation for both girls and boys. For example, among white populations, early maturation tends to be advantageous for boys, particularly with respect to their participation in sports activities and their social standing in school. By contrast, early maturation can be problematic for white girls, because the kinds of physical changes girls experience with puberty (such as weight gain) are not highly valued among many white American groups who value the slim, androgynous female body characteristic of white fashion models. In a 1987 study, Roberta Simmons and Dale Blyth found that early maturing white females had lower self-esteem and more difficulty adjusting to school transitions, particularly the transition from elementary to junior high school, than later maturing white females, white males, and both early and later maturing African-American females. Similarly, in a 1990 study in Sweden, Håkan Stattin and David Magnusson found that early maturing girls obtained less education and married earlier than their later maturing peers, because they were more likely to join older peer groups and date older males. In turn, these girls were more likely to drop out of school and get married, perhaps because school achievement was not valued by their peer social network while early entry into the job market and early marriage was. Early maturation does not have these kinds of effects in all cultural groups. For example, African-American females in the United States do not evidence these patterns.

Directly linked to the biological changes associated with puberty are the changes in both body architecture and emotions related to sexuality. Puberty is all about the emergence of sexuality. The physical changes of puberty both increase the individual's own interest in sex and turn the individual into a sexual object in other people's eyes. Both of these changes can have a profound impact on development. Sexual behavior increases dramatically during early to middle adolescence. With these increases go increases in pregnancy and sexually transmitted diseases. Both the frequency of these behaviors and the long-term consequences of these behaviors differ across cultural groups.