A new review published in the journal Developmental Cognitive Neuroscience argues that teenagers’ risky behaviors may be a matter of exploration rather than the result of an under-developed brain, which is the current popular theory.
In recent years, neuroscientists have proposed the theory that teenagers’ seemingly impulsive and risky behaviors may be linked to low development of the prefrontal cortex and its weak connectivity with brain reward regions.
In the new review, however, the researchers challenge that conclusion. They examined the evidence behind this popular notion and found that much of it misinterpreted adolescent exploratory behavior as impulsive and lacking in control. Instead, the review suggests that much of what looks like adolescent impulsivity is behavior that is guided more by curiosity or a desire to learn about the world.
“Not long ago, the explanation for teenage behavior was raging hormones,” said lead author Daniel Romer, Ph.D., research director of the Annenberg Public Policy Center of the University of Pennsylvania.
“Now, it’s that the prefrontal cortex isn’t fully developed. Neuroscientists were quick to interpret what appeared to be a characteristic of the developing brain as evidence of stereotypes about adolescent risk-taking. But these behaviors are not symptoms of a brain deficit.”
The authors say that the brain development theory fails to take into account the implications of different kinds of risk taking. For example, teens have a heightened attraction to new and exciting experiences, known as sensation seeking, which peaks during adolescence.
However, adolescents who exhibit that tendency alone are not necessarily more likely to develop health issues such as substance use or gambling addiction. In fact, the researchers say that the rise in adolescent levels of the neurotransmitter dopamine, which may be a driving force for sensation seeking, also supports the brain’s ability to exert greater control and to learn from experience.
“What’s happening is that adolescents lack experience,” Romer said. “So they’re trying things out for the first time, like learning how to drive. They’re also trying drugs, deciding what to wear and who to hang out with. For some youth, this leads to problems.
“But when you’re trying things for the first time, you sometimes make mistakes. Researchers have interpreted this as a lack of control when for most youth, it’s just exploration.”
Romer added, “The reason teens are doing all of this exploring and novelty seeking is to build experience so that they can do a better job in making the difficult and risky decisions in later life — decisions like ‘Should I take this job?’ or ‘Should I marry this person?’ There’s no doubt that this period of development is a challenge for parents, but that’s doesn’t mean that the adolescent brain is somehow deficient or lacking in control.”
The authors say that the stereotype of the risky adolescent is based more on the rise of such behavior in adolescence than on its prevalence.
“For the vast majority of adolescents,” the researchers write, “this period of development passes without substance dependence, sexually transmitted infection, pregnancy, homicide, depression, suicide, or death due to car crashes.”
In fact, it’s only a small subset of teens — those who exhibit impulsive behavior and have weak cognitive control — who are most at risk of unhealthy outcomes. These impulse control problems are often identified at ages four or five, and teens with these issues are disproportionately likely to experience the hazards of adolescence and beyond, including higher rates of injuries and illnesses from car crashes, violence, and sexually transmitted infections, the authors say.
“Further research is clearly needed to understand the brain development of youth who are at risk for adverse outcomes, as abnormalities of brain development are certainly linked to diverse neuropsychiatric conditions. This research will help us to understand not only what makes adolescence a period of growth but also of risk,” said co-author Theodore Satterthwaite, M.D., a faculty member in the Department of Psychiatry at the Perelman School of Medicine at the University of Pennsylvania.