Studies have shown that genetics, nutrition, parenting and mental illness all affect the way our brain develops and the way we behave in adolescence. And in our latest paper, we looked at three other factors that might affect brain development: socioeconomic status, relationships with peers and culture. The reason why most adolescent brain research hasn’t look at individual differences yet is partly because the field is only about 20 yearsold, and new research areas need to start with the basics – the averages – before they attempt to understand the nuance.