We know kids are drawn to risky behaviors, but why?
By Wendy B Smith, Ph.D. LCSW – PsychologyToday.com – January 18, 2026
KEY POINTS
- Delinquent crime rises sharply from age 10 and falls off at age 16.
- Adolescents experience rapid but uneven brain development and reward-driven activity takes precedence.
- Early-life trauma can create even greater risks for adolescents.
In the class of things that happen so often or predictably as to become truisms are the high-risk activities that teenagers frequently engage in, like driving too fast, using alcohol or drugs, unprotected sex, and delinquency. Decades of research report that across Western countries, delinquent behaviors rise sharply from age 10 until age 16 and fall off just as sharply in late adolescence and early adulthood, a phenomenon referred to as the “age-crime curve” (Scott & Steinberg, 2008).
Because these activities can result in immediate dangers and long-term negative consequences for young people and for others, greater knowledge and understanding of what’s happening developmentally in adolescent brains can be a vital part of helping vulnerable kids.
Adolescence is second only to early childhood in the rapidity and sheer volume of changes occurring in brain development. Three different brain systems (and their interconnections) are at play: reward-driven behavior, harm avoidance, and regulatory behavior. At the same time, teens are experiencing powerful changes to their physical and sexual selves, accompanied by the hormonal cascade of puberty.
Adolescent Brain Development
During this period, there is an increase in brain receptors for dopamine, a neurotransmitter that has a strong effect on the experience of pleasure. This increase in dopamine activity makes rewards seem even more rewarding, particularly in the presence of peers. At the same time, a decrease in activity in the area of the brain that is involved in response to danger or threat (the amygdala) makes negative outcomes seem less threatening (Evans-Chase, 2014).
In contrast, the areas involved in self-regulatory and executive processes such as planning ahead, weighing risks and rewards, response inhibition, and the ability to consider multiple sources of information simultaneously are slower to develop.
Adolescents show exaggerated response to anticipation of rewards, while their warning systems may be less sensitive to potentially harmful stimuli than those of adults (Smith, 2014). The activity of the reward system prevails over harm-avoidance functions, and the regulatory system of executive functions is not yet able to achieve a balance between these two.
The development of judgment and reason occurs over the next several years, well into the 20s. It is aided by the processes of pruning (unused neural connections fall away) and myelination (neurons acquire a coating of white material that increases the efficiency and coordination of connections between executive and regulatory parts of the brain controlling emotions, impulsivity, and decision-making).
Brain Development and Delinquency.
For all of us, adolescent development has its foundations in what we have already experienced. That includes the fundamentally important early caregiving relationship(s) and experiences, as well as environmental forces and factors. When these are benign and supportive, young people have what is needed to navigate the challenges of an immature regulatory system and the heightened sensitivity to rewards.
If, however, there has been trauma or victimization in a child’s life, brain development will be affected. Early occurring child abuse dysregulates the stress response system. leaving a teen more vulnerable to the risks of puberty and adolescence. Children need consistent attuned nurturing in the early years to promote effective behavioral regulation, reasonable interpretations of social cues, empathy, and emotional control.