Are preschoolers matched to their futures? New research links early development to rising adolescent anxiety

Adolescent anxiety is rising globally, especially in developed nations. While the COVID-19 pandemic worsened mental health in young people, it did so less than expected from the upward trend occurring before 2020, suggesting that current stress does not alone explain this trend.

A new hypothesis published in Science suggests that high rates of adolescent anxiety may be rooted in the earliest stages of life—even before birth. Professors Mark Hanson (University of Southampton) and Sir Peter Gluckman (University of Auckland) argue that early biological adaptations—once protective—are now mismatched to modern life.

An evolutionary mismatch

Anxiety evolved as a survival tool—an internal alarm system to detect danger.

In pregnancy, early environmental signals—like stress in the womb or infancy—can shape how a child’s brain responds to threats. These predictive adaptive responses prepare the body for the expected environment.

But what happens when that expected world doesn’t match reality?

In their paper, “ Growing anxious—Are preschoolers matched to their futures? ” , Professors Hanson and Gluckman explore how the environments we’re born into may no longer align with the environments we’re growing up in.

If signals in the womb or early childhood suggest a harsh, threatening environment, yet the child grows up in a fast-paced, digital world—where threats are more social than physical—those adaptations can misfire.

The result? Heightened anxiety, poor emotional regulation, depression, and a reduced ability to handle everyday stress.

In this way, the very processes that once helped humans survive may now be fuelling a modern mental health crisis in children and adolescents.

The critical window: prenatal to preschool

The researchers challenge the traditional diathesis-stress model—which focuses on predisposition plus later-life stress—and instead highlight the first 1,000 days—from pregnancy through early childhood—as the key period for shaping mental resilience.

The brain’s executive functions take shape in early childhood, meaning the ability to manage stress, build relationships, make decisions and maintain focus is largely shaped before age four.

Yet modern pressures—rising levels of maternal stress, limited caregiver interaction and the increasing presence of digital devices in family life—can interfere with early brain development, priming children for dangers that may never appear.

Moreover, because anxiety and fear can lead to a preference for authoritarian leadership, the rise in these mental health conditions can fuel the support for populist and far right political parties.

Rethinking government policy: a call for lifecourse solutions

Most government strategies for mental health begin too late—missing the critical window of early development. Professors Hanson and Gluckman call on policymakers to adopt a lifecourse approach, including:

• Prioritising maternal mental health during pregnancy
• Investing in responsive, high-quality early childhood care
• Shifting education and social policy to support early brain development

As societies around the world grapple with the growing mental health crisis and its consequences, this research argues that only integrated approaches across health, education and social policy can effectively tackle the root causes of anxiety disorders.