The evolutionary reason why you should FaceTime Mom and Dad
New paper shows the deep evolutionary connections of being socially integrated and positive health outcomes across a range of animals
Social animals — from primates to yellow-bellied marmots, dolphins and more — can help us better understand the role social interactions play in health and mortality, not just within their own species but in humans as well.
Noah Snyder-Mackler, an assistant professor of the Center for Evolutionary Medicine in Arizona State University's School of Life Sciences, talks about these connections in a groundbreaking synthesis he helped organize that resulted in a review article in the May 22 Science magazine.
Snyder-Mackler was part of a multiyear interdisciplinary working group on the social determinants of health in humans and other animals. The article, for which he is the lead author, brings together the disparate fields of evolutionary biology with sociology and epidemiology and finds that much can be learned from studying mammals and their social proclivities, especially as they relate to health.
Question: What does your paper outline?
Answer: This is the first effort, to our knowledge, to synthesize the evidence of social disparities in health and survival across many social animals, including humans. The goal was to bring together researchers from fields that have been addressing similar questions on social disparities in health, but using different systems and with different vocabularies and approaches.
It began with a working group organized at Duke, University of North Carolina and Wake Forest, where we brought together evolutionary biologists, demographers, behavioral ecologists, sociologists and epidemiologists, to identify the ways in which animal research could inform human studies of social disparities and vice versa. These two fields — evolutionary biology and sociology — don’t often communicate, living in somewhat parallel universes addressing pretty similar questions when it comes to understanding the consequences of social stratification on reproduction, health and survival.
We see this in humans. For example, a meta-analysis led by Julianne Holt-Lunstad showed being more socially connected has as strong or stronger of an effect on survival than quitting smoking or abstaining from drinking. There are many parallels in nonhuman animals, from mice to monkeys, showing that low social status and social isolation are associated with poor reproduction and health, and ultimately higher mortality.
Our Science review lays out the shared interests and similar findings, while also detailing some key shared avenues of future work where we can help develop a better understanding of the biology of social disparities in health and survival, which is what my lab focuses on.
Q: Seems like for humans and other animals these social groups help make them stronger and more resilient. Is this an effect that can be measured?
A: Humans are social animals, and we have evolved to thrive in social groups and with social interactions. So it's not surprising that these social interactions — or the absence of interactions — impact our health and well-being.
We would like to know how the social environment “gets under the skin” to affect our health and mortality risk. This is the focus of my research and is relevant to improving disease prediction, prevention and targeting interventions; understanding the causes and consequences of social inequality; and investigating the evolution of social group living and its relevance to human health.
We can measure it at multiple levels. At a high level we can see it in the population by observing changes in demographic patterns; in the individual, by examining overall health and well-being; and we see it when we zoom way down into individual tissues and cells.
My lab primarily focuses on the tissue and cell level. We use genomic tools to pinpoint some of the molecular mechanisms that are altered by our social experiences, which might be the key links between the social environment and health and survival. For instance, in one project we’re identifying molecular (epigenomic and transcriptomic) signatures of low social status (a measure of social adversity) that mimic the molecular signatures of aging in the immune system. So, looking to see how chronic social adversity can actually accelerate the aging of cells. My ultimate goal is to use this knowledge to find ways to mitigate the negative health effects of poor social experiences.
Q: If these social connections don’t exist, do animals become more fragile and less resilient?
A: Yes, there is connection between social environmental effects and health. This is the other side of the coin of the “social buffering” hypothesis, which suggests that social integration is protective for health because it dampens the deleterious consequences of acutely stressful events. If you are less connected, or have low social status, you have a less predictable environment, which can lead to lots of poor health outcomes. The thought is that with less predictability comes increased stress reactivity, which itself leads to a hyperactive inflammatory system. Many of the noncommunicable diseases we see today are linked to chronic inflammation. The emphasis here is on noncommunicable — isolation certainly prevents you from getting infectious diseases, which is why we’re socially distancing right now.
Q: Can this be applied to the situation today with COVID-19 pandemic?
A: I think it is pretty timely, even before the COVID-19 crisis. Each year we accumulate more and more evidence of social gradients in health across environments and societies. We also have mounting evidence that social isolation is associated with a higher risk of mortality — something that pushed the U.K. in 2018 to appoint its first minister for loneliness. This is particularly relevant during a time when we are social distancing to prevent the spread of a dangerous virus. I don't want to speculate that this period of social distancing is going to drastically affect health and survival, though it certainly is acutely affecting mental health. I think that any negative consequences of social distancing are far outweighed by the positive impact it is having to curb the spread of the virus.
Additionally, we're seeing that some of the most severe cases of COVID-19 happen to individuals with preexisting health conditions, which themselves exhibit a social gradient that is not unique to humans. This means that the current pandemic is amplifying health gradients that already exist in society, which emphasizes the need for us to implement policies and solutions that mitigate these gradients.
Q: So how can we stay socially "healthy" during social distancing?
A: While you may not be able to physically be with your friends and family, you can do so virtually. So call your grandparents, FaceTime your family, text your friends. These connections are deeply rooted in our evolutionary history and can help buffer us from the negative health consequences associated with these uncertain times.