Lonely teens are more likely to lash out at others – and boys are disproportionately impacted on both sides

Teenagers who feel lonely or experience conflict at home are more likely to act aggressively toward their peers, according to study involving more than 10,000 American children.

The research, from the University of California at Davis, was drawn from wider data collected from children and teens between the ages of 10 and 13 years old.

Teenage boys are disproportionately impacted on both sides – likely to be both the aggressors or victims of aggression, the study found. Teen girls are more likely to have fewer friends, but less likely to act aggressively.

The research was part of the work at the Teen Experiences, Emotions & Neurodevelopment (TEEN) Lab, which examines teen behavior and processes in their brains.

These findings could help experts to better understand teens and uncover ways to improve relationships in that age group in the future, the researchers said Tuesday. The research is “an important step in identifying the various facets of how adolescents begin to build close relationships with peers,” Amanda Guyer, a professor of human ecology at the school, explained in a statement.

The data used in the study was collected from the 2015 National Institutes of Health-funded Adolescent Brain Cognitive Development Study. Nicknamed the “ABCD Study,” it is the largest long-term study of brain development and child health in the U.S., spanning 21 research sites and dozens of states.

The ABCD study followed the development of participants over the course of 10 years. It has helped researchers discover that adolescents who get more sleep are less likely to experience depression and anxiety and that screen time has a lower influence on Attention Deficit Hyperactivity Disorder than previously expected.

The data spans from 2015 through the first two years of the pandemic, a time that has been tied to worsened mental health and stress levels in teens.

“We recommend future research extend this preliminary analysis to assess the effect of the pandemic on adolescent social outcomes in the ABCD Study,” the Davis researchers wrote.

It’s been six years since the pandemic began, and those students have since graduated from college and entered the workforce. But, impacts to teen mental health can be seen long after they graduate high school, the researchers noted.

Previous studies show that people who have positive relationships as teenagers tend to have better mental health and are more able to manage stress in adulthood.

Positive relationships with parents and adults during childhood has been linked to better mental health as an adult – regardless of any other negative experiences, a Columbia University study conducted in 2023 found.

“Our study demonstrates that children who have at least one positive, committed adult-child relationship are less likely to experience depression, anxiety and perceived stress later in life,” Columbia psychiatrist Dr. Sara VanBronkhorst said then.