Dr Seffetullah Kuldas is currently a Postdoctoral Fellow at the Department of Psychology, Norwegian University of Science and Technology (NTNU). He is part of the Trondheim Early Secure Study (TESS) team, focusing on longitudinal changes in psychosocial development, mental health, and health behaviours from childhood through adolescence into emerging adulthood. In particular, he examines the relationships between physical activity and sleep over time. Additionally, he holds a temporary researcher position at the Department of Media and Communication, University of Oslo, where he conducts cross-national analyses of the EU Kids Online data, investigating the digital transformations of family life across European countries. His main research interests include:

• Inter-ethnic and intra-ethnic bullying and victimization
• Cross-national and cross-ethnic differences in parental mediation of children’s Internet use
• Educational resilience (e.g., against ethnicity-based bullying victimization)
• Self (individualistic vs collectivistic self-construal)
• The unconscious mind
• Motivation and achievement goals
• Cognitive load (working memory capacity)