Anxiety is an uncomfortable feeling. It can make us tense, uneasy, unable to relax. But what if we think of anxiety as a feature that once helped keep our ancestors alive rather than a flaw in the human brain?

That's the provocative idea behind a new study from the University of Cambridge which suggests that when talking to their patients, mental health professionals overwhelmingly prefer explaining anxiety as an evolved survival response, rather than as a condition of chronic worry rooted primarily in genetics.

Just as a smoke detector is designed to be overly sensitive because missing a real fire could be catastrophic, the human anxiety system evolved to react quickly and often.

The results are part of what researchers describe as the first major randomized controlled trial examining evolutionary psychiatry. The study involved 171 practicing mental health clinicians from the United Kingdom and Ireland, including psychiatrists, psychologists and other mental health professionals.

Participating clinicians were randomly assigned to receive one of two 30-minute educational sessions, one explaining anxiety through the lens of evolution and survival, the other focusing on genetics and hereditary risk factors. Researchers then used questionnaires before and after the session to assess how clinicians believed patients would respond to each approach.

The professionals were more than five times as likely to believe that evolutionary explanations would help patients compared to a genetic explanation. They were also more than three times as likely to say the evolutionary perspective would improve their own clinical understanding and treatment approach.

Researchers found clinicians believed patients would be significantly more hopeful about recovery and more willing to seek psychiatric help when anxiety was explained as a normal, evolved human response, rather than something “hardwired” into their DNA.

“Anxiety and fear are adaptive responses that evolved to help organisms, including humans, detect and avoid potential threats,” lead author Dr. Adam Hunt, a researcher in evolution in the Department of Archaeology at the University of Cambridge, said in a press release. “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 other words, anxiety may be less about defect and more about overprotection.

It helps people with anxiety to know that humans evolved in environments where threats were constant: predators, starvation, injury and social rejection could all threaten survival, the researchers explain. From an evolutionary perspective, it made sense for the brain to err on the side of caution. A false alarm was safer than missing a genuine danger.

The study highlights what researchers call the “Smoke Detector Principle.” Just as a smoke detector is designed to be overly sensitive because missing a real fire could be catastrophic, the human anxiety system evolved to react quickly and often, even if any of those alarms turn out to be unnecessary. The problem? That kind of ancient wiring may clash with modern life.

As anxiety rates continue to climb, researchers believe helping people understand why anxiety exists may become an important part of treatment itself.

Researchers suggest today's nonstop news cycle, social media pressure, online isolation and chronic stress can amplify the brain's threat-detection system. Social anxiety, for example, may stem from an evolved fear of exclusion from early human groups, where being rejected from the tribe once carried serious survival consequences.

“Social anxiety evolved as a tool for inclusion,” Hunt explained. “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.”

The researchers are not arguing that genetics play no role in anxiety. Anxiety disorders do tend to run in families and researchers estimate they are moderately heritable. But this study suggests that focusing too heavily on genetics unintentionally leaves patients feeling pessimistic or powerless about recovery.

Today's nonstop news cycle, social media pressure, online isolation and chronic stress can amplify the brain's threat-detection system.

The evolutionary approach, the research team says, may help reduce stigma while supporting treatments such as exposure therapy, which teaches the brain through repeated safe experiences that a feared situation is not actually dangerous.

According to the World Health Organization (WHO), an estimated 159 million people worldwide were living with anxiety disorders in 2021, a dramatic increase over recent decades. As anxiety rates continue to climb, researchers believe helping people understand why anxiety exists may become an important part of treatment itself.

The study is published in British Journal of Psychiatry.