\u201cIn our ancestral environments, we were well adapted to deal with acute stress<\/a> to evade or confront predators<\/a>,\u201d Shaw said in the study\u2019s accompanying release<\/a>.<\/p>\n \u201cThe lion <\/a>would come around occasionally, and you had to be ready to defend yourself\u2014or run. The key is that the lion goes away again.\u201d<\/p>\n Fight or Flight<\/p>\n Today’s stressors\u2014like traffic<\/a>, deadlines, noise and social media<\/a>\u2014may feel routine, but they trigger the same fight-or-flight systems as predatory threats did in the past, Longman noted.<\/p>\n \u201cWhether it\u2019s a difficult discussion with your boss or traffic noise, your stress response system is still the same as if you were facing lion after lion,\u201d he said.<\/p>\n \u201cAs a result, you have a very powerful response from your nervous system, but no recovery<\/a>.\u201d<\/p>\n According to the researchers, the mismatch between modern lifestyles<\/a> and ancestral biology<\/a> may be harming evolutionary fitness<\/a>\u2014defined as the ability to survive and reproduce.<\/p>\n Shaw and Longman point to declining global fertility<\/a>, chronic inflammation and reduced sperm <\/a>counts as symptoms<\/a> of stress-induced biological strain.<\/p>\n The consequences are wide-reaching. In an email to Newsweek<\/a>, Longman said his biggest takeaway from the study was, “how profound and pervasive,” the mismatch seems to be.<\/p>\n “It\u2019s not a single health issue,” he said, “It spans core systems. And what surprised me most was the strength and consistency of the evidence: physiology, epidemiology and evolutionary theory all point to the same conclusion.”<\/p>\n What to Know<\/p>\n The researchers found that key stress responses\u2014intended for short-term emergencies<\/a>\u2014are now constantly activated by modern living.<\/p>\n This persistent activation may impair everything from immune system performance to memory<\/a> and hormonal<\/a> balance.<\/p>\n Notably, sperm count and motility have dropped significantly since the 1950s, trends some studies<\/a> link to environmental pollutants<\/a> like microplastics<\/a> and pesticides<\/a>.<\/p>\n What People Are Saying<\/p>\n Longman said the mismatch, “isn\u2019t just persisting, it\u2019s potentially expanding,” citing the Great Acceleration of the mid-20th century as, “the real turning point”.<\/p>\n “Since then, urbanization, pollution, chemical exposure, microplastic accumulation, artificial light and noise have all increased at a pace far beyond what human physiology can realistically adapt to,” he told Newsweek.<\/p>\n “On top of these environmental shifts, the last two decades have added a new dimension: Constant digital connectivity, social media, 24\/7 information<\/a> flow and, more recently, [artificial intelligence<\/a>]-mediated interactions.<\/p>\n “Our stress-response systems evolved for short bursts of acute threat<\/a> and not for continuous notifications and the absence of genuine psychological ‘off-time.’ In that sense, the digital environment amplifies the mismatch created by industrialization.”<\/p>\n What\u2019s Next<\/p>\n The researchers <\/a>advocate for designing<\/a> cities<\/a> and workplaces that reflect human physiological needs.<\/p>\n Longman stressed, however, that cities are not the enemy.<\/p>\n “The point is that many urban environments currently lack the features our biology depends on and introduce novel stressors that we\u2019re not adapted to and are harmful to our biology,” he said.<\/p>\n Longman also noted that their study doesn’t come with a quick fix.<\/p>\n “This isn\u2019t just a ‘nice to have’ conversation about being more in nature,” he said.<\/p>\n “According to our analysis, exposure to natural environments is biologically necessary.”<\/p>\n![\"Stress\"](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/12\/GettyImages-2187915909.jpg\"\/)
Why it Matters<\/p>\n