Constantinos M. Kokkinos, PhD is Professor of Educational Psychology and Director of the Educational Psychology & Special Educational Needs Lab at the Department of Primary Education, Democritus University of Thrace, Greece. His research examines socio-emotional development, school bullying and cyber-aggression, personality and mental-health factors in young people. Additionally, he investigates how stable learner characteristics—such as Big-Five personality traits, motivational beliefs and attachment representations—shape the use of cognitive / metacognitive study strategies, classroom engagement and ultimately academic achievement. He has authored more than 100 peer-reviewed international journal articles and numerous book chapters. Recognized for his scholarly impact, he has appeared for five consecutive years (2020-2025) in Stanford University’s global list of the top 2 % most-cited scientists and has received successive Rector’s Awards from Democritus University. He serves on the editorial boards of Personality and Individual Differences, Educational Psychology, and Journal of Child & Adolescent Trauma, and is Associate Editor of Psychology: The Journal of the Hellenic Psychological Society.