Modern life is pushing human minds and bodies beyond the limits set by evolution, according to a new study.
Lead author Dr Jose Yong, of James Cook University in Singapore, told the Daily Mail that for more than 99 per cent of human history, people lived as hunter gatherers in small, kin based communities surrounded by nature. He said that in evolutionary terms, the shift to modern cities happened almost overnight.
Dr Yong compared humans to moths, whose instincts still have not caught up with the invention of electric lights, sending them flying toward their doom every evening. He and his co authors say this evolutionary mismatch is responsible for problems ranging from chronic anxiety to rising rates of obesity and short sightedness.
Homo sapiens emerged as a species 300,000 years ago, and for the overwhelming majority of that time, people lived in tiny, family based social groups. The researchers say instinctive responses to stress, conflict and social pressure were fine tuned by hundreds of thousands of years in those environments, but human society has since changed too rapidly and fundamentally for those old habits to still be useful.
Dr Yong said the social landscape people now navigate stretches far beyond anything their ancient ancestors could have envisioned. He said ancestors lived in small, relatively egalitarian communities surrounded by people they knew well, while many city dwellers today are surrounded by thousands of unrelated strangers and are constantly exposed to people with far greater wealth, status or success. He added that social media has allowed these interactions to play out to their logical extremes.
In hunter gatherer groups, it was easy to know where a person stood in the social order, and competition was generally minimal and healthy, the researchers said. Today, the inequalities and uncertainty people face daily drive them into a constant state of comparison and competition, creating a feedback loop in which inequality drives competition that in turn fuels even greater inequality.
Dr Yong calls this the Social Evolutionary Mismatch and Competition Hypothesis and says it could be the root of a wide range of problems facing the world today. The research, published in the journal Behavioural Sciences, links the mismatch to a rise in psychological disorders, overstimulation, cognitive overload, social disconnection, depression and suicidality. The researchers also suggest the mismatch could be behind falling fertility rates, as people spend more time competing for status and resources rather than building families.
A changed physical world
Dr Yong said it is not just the social world that has changed faster than human brains and bodies can adapt to. He argues the material world is now so different from hunter gatherer origins that it is causing serious physical and mental health problems, with natural environments largely replaced by artificial habitats filled with technology.
Diets have also been transformed in just the last 200 years, replacing natural products with highly processed, high calorie alternatives, the researchers said. Dr Yong said people often report feeling more relaxed after spending time in nature, and that childhood myopia is more common when children have less exposure to outdoor environments. He said artificial lighting interferes with natural circadian rhythms, while many people working office jobs spend most of the day sitting despite having evolved to benefit from regular movement.
An era of 'polycrisis'
The researchers also warn of a larger change in the world, arguing it has entered an era of "polycrisis" in which multiple crises entangle and spill into one another. As an example, they say climate change increases the frequency of droughts and crop failures, which drives up the cost of living, which in turn fuels political unrest and makes governments more inward looking and less willing to cooperate on shared challenges such as climate change.
Dr Yong said the result is that the world feels increasingly unstable, people feel like they are constantly in crisis mode, and there is no single clear solution to reverse the trend. He said the most troubling possibility is that some forms of evolutionary mismatch are pushing humanity toward what evolutionary biologists call an evolutionary trap, where behaviors that were once adaptive become persistently maladaptive because the environment has changed, while people continue responding with instincts suited to a different world.
The researchers explain that an evolutionary mismatch creates a world that feels more competitive, which naturally makes people become more competitive in response. The problem, they say, is that when everyone does this, the world becomes more hostile and competitive for everyone else.
Despite the bleak picture, the researchers suggest change is still possible. They propose that cities could be built with spaces that feel less crowded and overwhelming, while encouraging people to spend time in nature. They also suggest social media should be redesigned to reduce the intensity of competition between people rather than drive it to a fever pitch.
