Schoolyard conflict could lead to heart disease and diabetes later in life

New research published in the journal Health Psychology has revealed that aggressive behaviour during teenage years is linked to accelerated biological ageing by midlife.

The study suggests that the intense stress associated with constant conflict in youth, if carried into adulthood, likely contributes to a faster internal "clock".

This biological advancement can significantly increase a person’s lifelong risk of developing chronic health conditions, such as heart disease and diabetes.

Led by Joseph Allen, a professor of psychology, the research team tracked a group of students from the age of 13. “Adolescents are often mocked for treating their relationship as matters of life and death,” Allen noted in a release.

To measure the impact of social friction, the team collected long-term data on aggression, family conflict, and peer relationship problems.

They utilised two validated methods—incorporating factors like blood pressure, inflammation, blood sugar, and immune function—to compare a participant's biological age against their actual age. The findings showed that higher levels of early adolescent aggression predicted a more advanced biological age by 30.

This trend remained consistent even after accounting for variables such as gender, income, and childhood illness.

Interestingly, the study noted that boys often experienced more conflict with fathers, while those from lower-income backgrounds were more likely to act out against peers.

While Allen cautioned that other unmeasured factors might play a role, he stressed that what truly matters is how these early behaviours evolve into later relationship struggles, underscoring the enduring health consequences of early social challenges.