Nature, nurture, and the global experience of adolescence.
Posted Feb 02, 2012
Most of us think we know what adolescence is about. It's about being a teenager, rebelling against parents, perking up to the opposite sex, making impulsive decisions, searching for identity, and the like. Adolescence is a complicated life stage for the same reason it fascinates us—because it's a volatile brew of biological, psychological, and social transformations. But how much of adolescence is simply a part of being human, and how much is a product of cultural upbringing?
The World Health Organization defines adolescence as the age range between 10 and 19 years, but that definition fails to capture reality in some societies. In Bangladesh, for example, childhood ends when the child becomes employed. For the Hmong of Laos, children abruptly become adults at the age of 11 or 12. Although the length and endpoints vary, most societies recognize a distinct life stage that is organized around puberty and the development of reproductive capabilities.
Adolescence can be understood as a time of great change in the brain's structure. Neuroscientist B. J. Casey, director of the Sackler Institute at Weill Medical College of Cornell University, and her colleagues have sought to explain the suboptimal decisions of adolescents (in other words, why they act so dumb). Numerous fMRI studies show that the adolescent brain is highly developed in subcortical regions, like the amygdala and nucleus accumbens, that are associated with emotionality. At the same time, the adolescent prefrontal cortex—a region associated with higher mental processes like planning and decision making—develops slowly and isn't fully formed until a teenager becomes a twenty-something. This differential pace in rewiring leads to a tendency for adolescents to behave irrationally when faced with emotionally-weighted information-to discount the possibility of adverse outcomes, for example.
If adolescence is biologically dictated, then we should expect it to look the same, more or less, across cultures and in similar species. And it does, to a degree. Adolescents everywhere, when compared to their child and adult selves, explore more, take more risks, and interact more often with peers. These behaviors are commonly observed among adolescents in virtually all human societies but also in baboons, macaques, and even elephants.
Schlegel and Barry noted another common feature of adolescence in their analysis of ethnographies. Young people contribute to family life and the wider community by helping out with chores, cleaning streets, preparing for community festivals and the like. Another study, however, found that different societies have different expectations about just how helpful adolescents should be. In 1999, Reed Larson and Suman Verma investigated how children and teens in different parts of the world used their time. They found that teens in Japan and China typically spent far less time helping out around the house than did teens in North America. The difference may have to do with the emphasis on self-sufficiency and individualism that is common in the West. American parents said they assigned chores in order to build individual responsibility. Chinese and Japanese parents, on the other hand, feared that piling on the chores would take away time for schoolwork, which is highly valued in the Confucian tradition.
The phenomenon of adolescence, like most psychological phenomena, has universal features and culturally-variable features, biological components and social components. It is a life stage defined by the intersection of nature and nurture. We're still a long way off from understanding adolescence completely, but with the concerted effort of experts, from neuroscientists to ethnographers to compassionate parents, we're getting closer all the time. Until then, the adolescent who tearfully insists, "You don't know what it's like!" is more right than he or she could ever know.
Casey, B.J., Jones, R.M., & Hare, T.A. (2008). The adolescent brain. Developmental Review, 28, 62-77.
Larson, R.W., & Verma, S. (1999). How children and adolescents spend time across the world: Work, play, and developmental opportunities. Psychological Bulletin, 125(6), 701-736.
Schlegel, A., & Berry. H. (1995). A cross-cultural approach to adolescence. Ethos, 23(1), 15-32.
World Health Organization (2005). Child and adolescent mental health policies and plans. Mental Health Policy and Service Guidance Package. Retrieved from http://www.who.int/mental_health/policy/services/9_child%20ado_WEB_07.pdf