Although adolescents' exposure to harmful online content has been linked to decreased subjective well-being and offline risky behaviors, there is limited research on the factors that underlie such problematic online behavior. Using the conceptual framework of Problem Behavior Theory, this study examined the role of risk (i.e., emotional problems, sensation seeking) and protective (i.e., the quality of family environment, social support from friends) factors in exposure to harmful online content among 4473 12- to 16-year-olds (M = 13.9, SD = 1.3, 49% girls) in the Czech Republic, Finland, and Spain. Individual country samples included 1848 adolescents from the Czech Republic (age: M = 14, SD = 1.4; 51% girls), 788 from Finland (age: M = 13.9, SD = 1.3; 52% girls), and 1837 from Spain (age: M = 13.5, SD = 1.2; 47% girls). In all of the sampled countries, emotional problems and sensation seeking served as risk factors, whereas good family relationships were protective. In some countries, the effects of emotional problems and sensation seeking were moderated by the quality of the family environment and social support from friends. These moderating effects suggest that individual risk factors for exposure to harmful online content may be buffered by a positive family environment and friends' support. The findings revealed similarities in the risk and protective factors underlying online problem behavior across three different countries. They demonstrate that the mechanisms proposed by Problem Behavior Theory can help to understand the etiology of adolescent problem behavior across different countries as well as offline and online contexts.

• Klíčová slova
• Emotional problems, Harmful online content, Problem behavior theory, Quality of family environment, Sensation seeking, Social support from friends,
• MeSH
• chování mladistvých * MeSH
• interpersonální vztahy MeSH
• lidé MeSH
• mladiství MeSH
• ochranné faktory MeSH
• přátelé * MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Finsko MeSH