Clinicians find evolutionary explanations for anxiety more helpful than genetics

Mental health clinicians are over five times more likely to see evolutionary explanations of anxiety as helpful for their patients, rather than the genetic approaches currently taught to trainee doctors and psychiatrists in the UK and US, a new study shows.

Research led by the University of Cambridge also found that clinicians across the UK and Ireland are three times more likely to rate a human evolution perspective on anxiety as useful for their own practice and understanding, compared to hereditary accounts.

Explaining how anxiety helped our species to survive and thrive – essentially, a naturally evolved defensive response that can get triggered too easily – provides vital context and a more positive outlook than describing anxiety as possibly "hardwired" into a person's DNA, argue researchers.

They say that anxiety is linked to "ancestral threats": from running out of food to social rejection from early hunter-gatherer tribes. Aspects of the modern world, such as online socialising and constant exposure to news, can "amplify the worry response and push some individuals into the pathological range."

"Anxiety and fear are adaptive responses that evolved to help organisms, including humans, detect and avoid potential threats," said Dr Adam Hunt, a researcher in evolution from Cambridge's Department of Archaeology who led the study, published in the British Journal of Psychiatry.

"Understanding anxiety as a deeply rooted survival function that has overshot the mark helps patients see their symptoms as exaggerated versions of a positive mechanism, and not evidence of a broken or abnormal brain."

In an accompanying report by the Foundation for Evolution and Mental Health, chaired by Hunt, experts call for a few hours of evolutionary teaching to be added to psychiatric and mental health training, along with public resources that outline the evolutionary usefulness of anxiety.

"With the growth of mental health diagnoses in recent years, the question becomes ever more pressing as to why these conditions exist," said Hunt.

"Neuroscientists spend billions of dollars zooming in on genes and rat brains. The assumption that the right level of magnification will provide answers hasn't been working out. Evolution, the fundamental theory which explains all biology, is an obvious place to look."

"If doctors are swamped by anxiety-related appointments, evolutionary ideas may help treat people concerned for their wellbeing who don't necessarily need medicalisation."

According to the World Health Organization, 359 million people worldwide lived with an anxiety disorder in 2021, a rise of more than 55% since 1990. A quarter of 16–24-year-olds in England report having a common mental health condition such as anxiety.

For the latest study, an international team of anthropologists and psychiatrists randomly assigned 171 practising mental health clinicians from across the UK and Ireland a 30-minute session on either an evolutionary explanation for anxiety or a genetic one, based on the latest scientific thinking in both fields.

Pre- and post-session questionnaires assessed clinicians' optimism for how effective they thought each "psychoeducation" intervention was likely to be, and the expected patient willingness to seek help as a result.

Clinicians overwhelmingly favoured evolutionary explanations. They were over five times more likely to find evolution rather than genetics useful for patients, and over three times more likely to believe it would improve their treatment approach.

The clinicians also believed that people would be much more willing to seek psychiatric help if evolutionary explanations were widely known (around 80% higher than for genetic explanations), and were about 60% more likely to think that patients with anxiety could recover when helped by an evolutionary perspective.

"We found a lot of enthusiasm among psychiatrists for the potential of evolutionary ideas to promote more hopeful and therapeutically empowering attitudes," said study co-author Dr Tom Carpenter, a registrar in psychiatry at NHS Greater Glasgow & Clyde.

Importantly, differences between the two groups of clinicians were driven by both positive effects of evolutionary education and negative effects of genetic education.

The genetic presentation highlights studies showing anxiety disorders are moderately heritable (by approximately 20–60%), which may help explain familial patterns of anxiety, and how "polygenic scores" – risk factors arising from thousands of tiny genetic differences – may eventually help identify and guide prevention strategies.

"The genetic framing actively worsened some clinician attitudes, increasing their belief that it would make patients pessimistic about recovery," said Hunt.

The evolutionary presentation uses the "Smoke Detector Principle" to explain why anxiety evolved to be biased toward false alarms: existential threats from predators, starvation or ostracisation in the deep history of our species made it safer to respond too often than miss a genuine danger.

Hunt points out that different types of anxiety evolved to address certain ancestral threats, producing clear physiological and behavioral responses.

For example, anxiety related to predators and life‑threatening danger helps explain the sensitivity seen in panic disorders and agoraphobia, where open spaces or situations in which escape may be difficult signal vulnerability.

Specific phobias reflect exaggerated fear responses to stimuli such as animals, heights, or confined spaces. Social anxiety can be understood in relation to the risk of status loss or being abandoned by the group, which carried serious consequences for survival and reproductive success – and still does.

"Social anxiety evolved as a tool for inclusion. Having people who are highly neurotic in a tribe makes a lot of sense. We see it in our friend and family groups, where anxious people are often those thinking ahead or picking up on social cues to prevent disharmony," said Hunt.

"But now, when people spend long hours and days alone, or with just the internet, they lack the consistent feedback of acceptance. It's instinctive for some to catastrophize."

Hunt says he hears from psychiatrists who find that young people are leaning into an anxiety diagnosis as a reason to stop interacting with people, whereas they should be aiming for the complete opposite.

"Every organism must learn which parts of its environment are dangerous and which are not. It is among the most ancient learning mechanisms in biology and a success story of adaptation," said Hunt.

"Exposure therapy targets these evolved learning systems by using repeated safe experiences to teach the brain that a stimulus is not a threat. Being in a tribe is a kind of constant exposure therapy for social anxiety. Humans and our lineage have spent millions of years in each other's company," he said. 

"The goal is not to replace existing psychiatry with slogans about evolution. It is to enrich frontline mental health work with a deeper understanding of human nature."

He points out that Charles Darwin – a University of Cambridge alumnus – predicted his work on evolution would eventually help us understand the spectrums of neurodiversity that underpin human communities.