A multinational study of more than 58,000 adolescents across 21 countries has identified a powerful and potentially preventable correlate of youth crime: unstructured free time. Defined as periods when young people are neither supervised by adults nor engaged in activities organized around educational, cultural, or athletic goals, this kind of time was consistently associated with delinquent behavior and exposure to violence across very different cultural settings.
Published in PLOS ONE, the study was conducted by researchers from the International Self-Report Delinquency Study consortium, a global research network that examines adolescent crime and victimization through anonymous questionnaires. The findings suggest that how young people spend their unsupervised hours may be an important part of the social environment in which violence and delinquency emerge. The researchers stress, however, that free time itself is not inherently dangerous. The risks appear to depend on where that time is spent, who adolescents are with, what opportunities are available, and whether supportive adults or institutions are present.
The study examined two broad forms of unstructured time. The first occurred outside the home, including hours spent wandering through streets, neighborhoods, and public spaces without adult supervision or a defined activity. The second occurred at home and was particularly connected with unsupervised internet use. In both settings, adolescents may encounter situations that increase access to risky behavior, expose them to aggressive models, or place them in contact with peers and environments where offenses are more likely to occur.
The strongest predictor of adolescent involvement in crime was association with delinquent peers. Unstructured free time ranked closely behind it as a cross-cultural explanatory factor. The combination was especially concerning: adolescents who spent substantial unsupervised time with peers already involved in delinquency faced a considerably more problematic social context than those exposed to either factor alone. This pattern is consistent with theories of routine activity and social learning, which propose that offenses become more likely when motivated individuals, suitable targets, and weak guardianship converge—and when young people observe and reinforce one another’s behavior.
The researchers analyzed data from the fourth wave of the International Self-Report Delinquency Study. Brazil contributed approximately 1,900 adolescents between the ages of 13 and 17 from public and private schools in Ribeirão Preto and Sertãozinho, in São Paulo state. Students completed anonymous questionnaires on tablets, allowing investigators to ask about specific behaviors rather than relying only on official police or court records. For example, participants were asked whether they had entered a store, taken an item, and left without paying. This self-report method can reveal behavior that never reaches law enforcement, offering a broader view of adolescent delinquency than administrative data alone.
The survey also measured victimization and the overlap between offending and being harmed. Adolescents reported whether they had experienced offenses connected with characteristics such as skin color, religion, sexual orientation, or physical appearance, either in person or online. One notable finding was the growing participation of girls in online offenses, particularly harassment involving other people’s appearance. Researchers suggest that traditional gender differences in parental supervision may be narrowing in digital spaces, where girls who might receive closer monitoring in the physical world can encounter greater autonomy and less direct oversight.
Girls were also more likely to fall into the category known as victim-aggressor overlap: adolescents who both experience and perpetrate violence. This group displayed more severe indicators of psychological distress, family difficulties, and academic problems. The pattern highlights why youth violence cannot be understood only as a matter of individual choice or criminal intent. Repeated exposure to violence may shape emotional regulation, relationships, school engagement, and expectations about how conflicts are resolved, creating cycles in which victimization and aggression reinforce one another.
The study’s sample consisted of students who were currently attending school, meaning that some of the most vulnerable adolescents were not represented. Young people who had dropped out, were disconnected from conventional institutions, or were involved in Brazil’s socio-educational system were excluded from the school-based sample. According to Marina Rezende Bazon, a psychologist and professor at the University of São Paulo who coordinates the Brazilian ISRD team, the association between unstructured time and delinquency could be even stronger among adolescents who spend years outside school and without effective contact with social-support networks.
The researchers also caution against interpreting juvenile crime as a problem limited to poor communities. Self-reported delinquency occurs across socioeconomic groups, but social class strongly influences who is monitored, stopped by police, prosecuted, or institutionalized. Official statistics therefore reflect not only offending itself but also the unequal operation of law enforcement and social-control systems. This distinction is essential when designing prevention policies, since programs that simply increase surveillance may intensify inequality without addressing the conditions that make young people vulnerable.
The study offers a concrete estimate of the potential value of structured alternatives. Across the full sample, a 20 percent reduction in unstructured free time spent away from home was associated with a 9.6 percent decrease in the prevalence of offenses and a 7.4 percent reduction in offense incidence. These figures describe statistical associations, not proof that reducing free time alone will prevent crime. Effective interventions would need to offer activities that adolescents genuinely value, including sports, arts, cultural programs, mentoring, and community projects led by trained adults or social educators. Simply occupying young people’s schedules may have little effect if the alternatives are inaccessible, unsafe, or disconnected from their interests and identities.
Online free time presents a more complicated challenge. Digital environments can expose adolescents to hate speech, harassment, criminal networks, violent content, and opportunities for harmful behavior. At the same time, the internet is a central setting for contemporary social life, education, creativity, and identity formation. Treating all unsupervised online activity as criminogenic would therefore be misleading. The researchers argue for digital education, family guidance, stronger online protections, and greater platform accountability, while recognizing that healthy autonomy is also part of adolescent development.
The ISRD consortium is preparing its fifth wave of research, which will examine misogyny, online hate crimes, and adverse childhood experiences such as abuse, neglect, domestic violence, and living with substance abuse or severe mental-health problems. These experiences can produce chronic or “toxic” stress, a prolonged biological and psychological response associated with later mental-health difficulties, academic disruption, violence, and recidivism. Taken together, the findings point to a broader prevention strategy: not merely keeping adolescents busy, but creating safe and meaningful routes into community life. The organization of young people’s daily routines may be one of the most practical places to intervene before violence becomes entrenched.
Subject of Research: Adolescent unstructured free time, delinquency, violence, victimization, and online behavior
Article Title: Unstructured spare time as an international predictor of adolescent crime
News Publication Date: 15 May 2026
Web References: https://doi.org/10.1371/journal.pone.0349291; https://www.fapesp.br/en; https://agencia.fapesp.br/en
References: PLOS ONE, “Unstructured spare time as an international predictor of adolescent crime,” DOI: 10.1371/journal.pone.0349291
Keywords: adolescents, youth violence, juvenile delinquency, unstructured free time, peer influence, victimization, online offenses, crime prevention, adolescent mental health, International Self-Report Delinquency Study
