The Impact of COVID-19 on Our Mental Health…According to Evolutionary Science

Art by Yige Xu

Humans are a social species. In my four years of studying human evolution and cultural ecology, I have come to appreciate just how much humans rely on social interactions and connectedness. 

Sure, I’ve learned heaps about evolutionary psychology and human behaviour, but I’ve also learned what it was like to be a student. A student in their supposed prime of social interaction, a student who experienced the hustle and bustle of life on campus before the COVID-19 pandemic and the contrasting desolation and loneliness during it. A student whose mental health suffered from it. Immensely.

Biological evolution, put simply, refers to the process by which a species develops from earlier forms into organisms better adapted to their environment. This process is spurred by selective pressures which you may sometimes hear referred to as evolutionary drive. This is, in essence, correct. Although I would argue it provides the false idea that evolution is a conscious choice by which animals, including us humans, think “oh no, fast leopard wants to eat me I will grow longer and stronger legs so I can run faster and escape.”

Well no, not quite. Evolution instead involves spontaneous mutations to the animal’s genetic code. Those random mutations often result in minute physiological and morphological differences that allow that individual to outcompete, successfully mate, and therefore pass on their genes. That is true of the mutations that are adaptive, at least. In fact, I would wager a guess that the majority of these random mutations either make no difference whatsoever or develop to be maladaptive. Those maladaptive individuals cark it, taking their defective genes with them as they go.

Now that I’ve explained that, I have one more thing to clarify. Humans are, of course, still capable of evolving, however, the biological process of changing our entire genetic makeup to adapt to a not-so-satisfactory environment is slow and tedious and, as I’ve already said, seemingly random. Instead, we alter our environment to suit us through culture and technology. If Earth’s average temperature were to suddenly drop 20 degrees, we wouldn’t wait around for thousands of years to develop a thick layer of blubber like the mammals of the arctic. No, we’d just put on a coat. This is why, when studying the evolutionary responses of humans to various stressors including those posed by the COVID-19 pandemic, we shouldn’t look at ourselves today. Instead, we should consider the environment of evolutionary adaptedness (EEA), which is the hypothesised ancestral environment to which a species is adapted. Through considering the EEA, we can predict the selective pressures that shaped human evolution and therefore better understand how we came to look the way we look, act the way we act, and feel the way we feel.

Like me, I have felt alone and isolated during this pandemic.

Many species of primates will spend hours of their day sitting in each other’s company and picking the bugs out of their hair as a means of forming trust. It is no wonder we crave touch. Chimpanzees, our closest living relatives, have been known to band together to kill outsiders because they are seen as a threat and do not contribute to the subsistence of the group, which parallels our own fears of not fitting in. From archaeological evidence, we can deduce that the EEA for our human ancestors was likely one that relied on group living in order to survive. EEA allowed them to find a mate and pass on their genes, in the same way these primates do. Thus, it is no wonder we crave human interaction. Sociality is so fundamental to our survival, it is just as important as finding food or shelter. 

The point I am trying to make is that it is not only completely acceptable to feel lonely, inoperable, and depressed during these times of COVID-19 isolation, but that it is something that can be explained by evolution. Human connectedness is a survival mechanism. We not only crave it, we need it to survive.

Studies have shown that social isolation, as well as the self-perception of isolation and loneliness, has terrible consequences for short and long-term physical and cognitive health. It impairs sleep, immunity, energy levels, and increases the risk of dementia by up to 40%. Further studies have linked social exclusion and withdrawal with depression, and prolonged loneliness with mortality. Shockingly, one study revealed that loneliness has such an immense impact on our health and wellbeing that it can increase our risk of death by 45%. Clearly we are not evolved to be alone.

So, has human interaction evolved since COVID-19? I would suggest not. The psychological – and in some individuals’ cases, the physiological – toll that the pandemic has taken on all of us was unavoidable. If we consider just how heavily ingrained sociality is in our way of life, it is no wonder we are experiencing health repercussions  yearning for the days before isolation. We had freedom before: freedom to see our friends whenever we wanted, to visit our family and loved ones across the globe, and even freedom to have a short conversation with the barista at your favourite coffee shop and not worry if you had stood too close. Perhaps, these were all things we took for granted. Perhaps, these were all elements of the human experience that make us happier, and in turn, healthier.

As we slowly emerge from the COVID-19 pandemic and settle into the new normal of living alongside this virus, I imagine we will have a greater appreciation for human connectedness. I look forward to living in a world that appreciates everyday interactions and values authenticity, connection, and kindness. I believe that, through understanding how deeply entrenched sociality was during the time our ancestors evolved, we can have a greater awareness of – and appreciation for – just how valuable human interaction is. Then maybe, we will all take that extra moment to say “hello”.


Originally published in Woroni Vol.72 Issue 1 ‘Evolution’

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