An enigmatic age

A psychology professor gives a tour of a complicated stage of life.

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Every adult has gone through adolescence, yet studies of this stage of life may still be in their infancy.

For example, many psychologists struggle to define when adolescence starts and what it means to be an adult, says Professor of Psychology Monica Luciana.

Monica Luciana
Monica Luciana, Professor, Psychology

“In Western culture, everyone has begun to question notions of adolescence,” she says. However, “It’s recognized as a time of transition—storm and stress.”

But progress is being made.

About 20 years ago, researchers began to focus on the development of “executive function,” the set of “adult” abilities like planning, focusing attention, and self-control. Executive function is associated with activity in the prefrontal (cerebral) cortex.

More recently, says Luciana, researchers have become less concerned with the prefrontal cortex per se and more with the connections it makes with brain regions such as those of the limbic system, which is involved in emotions. During adolescence, some connections weaken, others strengthen, and attention tends to shift from parents to peers.

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Inside story

The key to the neurological changes in adolescence may lie with the brain chemical dopamine.

In adolescence the dopamine system becomes more active, Luciana says. Hormonal changes in puberty could trigger the system, which drives the motivational striving that adolescents experience and nudges them toward more independence and exploration.

Motivation matters—a lot

Studies of prefrontal cortex functioning have shown that by mid-adolescence, people are capable of advanced cognition and decision-making—but everyday actions don’t necessarily reflect an individual’s capabilities.

By age 16, adolescents tested in the lab show a nearly adult capacity for cognition, plus a high level of executive function and good judgment. Yet that’s when many start behaving in less-than-prudent ways with peers, Luciana notes.

“That led us in the field to recognize the importance of the context,” she says. “It’s an absolutely fundamental driver of behavior. For example, who are their friends, who are they trying to impress, what specific motivations do they have in those moments?” The disconnect between how adolescents function in the lab vs. real life happens because their adultlike capacity for control gets overwhelmed by more demands—from friends, social media, etc.—than it can handle.

“This taxes the control system and impedes self-regulation,” says Luciana. On the up side, she adds, “Those [peer-related] behaviors allow humans to move away from parents, reproduce without inbreeding, and explore the world.”

Monica Luciana is a scientist with the national Adolescent Brain Cognitive Development Study®. Watch the video “Giving back: One adolescent’s tale.”

Dig deeper

Monica Luciana is a professor in the Department of Psychology, College of Liberal Arts. Read a profile of her.

Kathleen Thomas, Damien Fair, and Michael Georgieff are professors in the Institute of Child Development within the College of Education and Human Development. Fair and Georgieff are also professors in the Department of Pediatrics within the Medical School, where Georgieff is also executive vice chair.

Watch a video about the Masonic Institute for the Developing Brain.