Related Experiment Video
Updated: Oct 27, 2025

Author Spotlight: Understanding Adolescent Social Adversity Effects on Neurodevelopment in Mice
Published on: March 15, 2024
Worldwide increases in adolescent loneliness
Jean M Twenge1, Jonathan Haidt2, Andrew B Blake3
1San Diego State University, USA.
Introduction:
Several studies have documented increases in adolescent loneliness and depression in the U.S., UK, and Canada after 2012, but it is unknown whether these trends appear worldwide or whether they are linked to factors such as economic conditions, technology use, or changes in family size.
Methods:
The Programme for International Student Assessment (PISA) survey of 15- and 16-year-old students around the world included a 6-item measure of school loneliness in 2000, 2003, 2012, 2015, and 2018 (n = 1,049,784, 51% female) across 37 countries.
Results:
School loneliness increased 2012-2018 in 36 out of 37 countries. Worldwide, nearly twice as many adolescents in 2018 (vs. 2012) had elevated levels of school loneliness. Increases in loneliness were larger among girls than among boys and in countries with full measurement invariance. In multi-level modeling analyses, school loneliness was high when smartphone access and internet use were high. In contrast, higher unemployment rates predicted lower school loneliness. Income inequality, GDP, and total fertility rate (family size) were not significantly related to school loneliness when matched by year. School loneliness was positively correlated with negative affect and negatively correlated with positive affect and life satisfaction, suggesting the measure has broad implications for adolescent well-being.
Conclusions:
The psychological well-being of adolescents around the world began to decline after 2012, in conjunction with the rise of smartphone access and increased internet use, though causation cannot be proven and more years of data will provide a more complete picture.
Related Concept Videos
Cognitive Development During Adolescence
Erikson's Theory on Socioemotional Development during Adolescence
Influence of Parents and Peers on Identity
Parental Influence on Identity Development
Parents serve as primary guides and managers in an adolescent's life, offering support instrumental in decision-making and personal growth....
Self-Evaluation: Self-Enhancement and Self-Verification
Sources of Self-Esteem I: Family Experience
Bullying

