How social homeostasis can help us understand post-lockdown anxiety. 

BY Srushti Naik

March 2020 marked the beginning of global lockdowns in response to the COVID-19 pandemic. In the UK, we initially braced ourselves for a few weeks of strict quarantining to slow down the rapid transmission of the deadly COVID-19 virus. This acute period of isolation seemed daunting at the time. Little did we know that we were in for a tumultuous journey of social unrest for the next 16 months of our lives. Now, as we start to cautiously pivot back to normality, we can begin evaluating the mental impact of these restrictions using the principles of social homeostasis.

The neuroscience behind social homeostasis

Homeostasis is a self-regulating process which ensures the best possible conditions for functionality are maintained. Examples include regulation of our body temperature (i.e., thermoregulation), hunger and satiety signals, and blood sugar (i.e., plasma glucose) concentration. Within each homeostatic system there are 3 key features; 1) a sensor to detect changes in a specific factor, 2) a central processing system to compare the change to an optimum “set-point” 3), an “effector” to adjust the levels of that factor via various physiological mechanisms. In this way, balance is restored in a system by the successful interaction of these 3 components.

From a macro- perspective, social homeostasis would mean maintaining harmony within the hierarchy of the animal kingdom. On an individual level, however, we can class it as the ability of an individual to detect the quantity and quality of social contact, compare it to an established set-point, and then make adjustments to maintain a sound social balance with their external environment. This is an innate need of our species for survival and has therefore evolved over time to serve us well. If we imagine our social connections to be distributed on a spectrum, people are alerted when social connections are at either extreme of the spectrum (i.e., excessively absent, or excessively present) so that effector mechanisms can be activated to restore social balance. 

Acute vs. chronic social isolation and its impact on social homeostasis 

Paradoxically, social distancing helped protect our physical wellbeing to the detriment of our mental health. Behavioural research in rodent and human models shows us that, after an acute isolation period of 24 hours, people display increased affiliative behaviours to strengthen social bonding with others. In our bodies, this shows up as elevated levels of the infamous stress hormone cortisol (part of a family of hormones called glucocorticoids) and increased verbal communication with the people around us. Contrary to popular belief, elevated cortisol levels for a short period of time are actually beneficial because they make us more alert, with an increased heart rate, lowered sensitivity to pain and heightened memory. This results in an overall increase in the energy spent to seek social contact.  Indeed, this may explain the proactive measures we all took in the initial stages of the first lockdown to increase our social contact by hosting zoom meet-ups, games, and activities with our loved ones.   

When we are chronically isolated however (i.e., for 3 months or more), these engagement behaviours are replaced with antisocial tendencies such as anxiety, aggression, and avoidance. This is evident in human, rodent, and fly models; the underlying biological mechanism for this is known as ‘neuromodulation’. Neuromodulation is a process which regulates the activity of neurons by controlling the level of chemical messengers in our brain (i.e., neurotransmitters). Cholecystokinin (CCK) is one such neurotransmitter that is involved in negative affective-state illnesses like anxiety and panic disorders in humans. A study from 2004 found that individually-housed male rats that displayed more  aggressive behaviours when faced with an intruder had higher CCK levels in certain brain areas called posterior cortex and tegmentum, compared with rats who did not display aggression. These findings highlight that a novel encounter after chronic isolation can result in increased aggressive tendencies. Though we cannot directly translate these findings to humans, we can see why spending an extensive period of time living in isolation can make us habituated to our space. This may  explain some of the discomfort some may feel with the easing of the lockdown, with our homes and other isolated spaces getting populated with friends and family. 

Apart from actual isolation, direct or indirect perception of loneliness (when we feel lonely even if people are physically present in our life) is also strongly associated with illnesses like cancers and cardiovascular diseases. A 2020 study found that perceived loneliness results in increased communication in specific brain regions called the pre-frontal cortex and the default-mode network. This shows up in our behaviour as rumination (the act of “mulling over” some deep and troubling thoughts and feelings) to fill the social void of loneliness, This could explain the deep sense of emptiness  that most of us felt at some point during the past year. We were fortunate enough to have the opportunity for virtual social connection in the 21st century, however perceived loneliness still affected us because we were unable to physically touch and feel the proximity of our loved ones through our screens. 

Post-lockdown anxiety – hypervigilance   

Once again, rodent research provides us with key insights on the impact of a social deficit with two crucial adaptations; hypervigilance (i.e., increased alertness) and social motivation. In terms of hypervigilance, researchers found that adult rats showed increased escape-related and self-grooming behaviours over days 1-4 of isolation, as well as a decrease in exploratory behaviour of their environment. One might say that these behaviours mirror what is happening with humans right now. With the opening of beauty salons, gyms, and other recreational facilities that encourage self-grooming in some way, we are seeing a surge in the number of people subscribing to these facilities.  Additionally, there is also an increase in escape-related behaviours, with people booking holidays abroad or countryside staycations over the coming months, made evident by the 400% increase in bookings to amber-list destinations from 19th July 2021.

Post-lockdown excitement – social motivation

A social neuroscience model proposes that loneliness works as a signal to encourage individuals to  overcome the  vulnerability of being alone by reconnecting with  people.  After 7 days of social isolation in adult rats, certain overlapping neural circuits in the brain work together to increase an individual’s attention to environmental stimuli and to reduce emotional distress via  increased social connectivity. One study tested this using the “conditioned place preference” assay (CCP). In this, over a 24-hour period, animals demonstrated a preference for regions of social housing rather than isolated housing, potentially motivated to gain the social reward as well as avoiding isolation. This can apply to us humans too, since we are we are motivated by the prospect of socially rewarding experience of meeting people, as well as escape from isolation. In one study, the absence of a social stimulus caused mice to avoid receiving stimulation of the dorsal raphe neurons (i.e., neurons that produce the hormone dopamine – a neurotransmitter that allows us to feel pleasure) which implies that a negative affective state was induced in these mice. This could mean that these neurons are recruited after isolation to create a “negative drive”  which will consequently act as social motivation and push the mice to seek social connection. Once again, this explains the rapid rush to meet up with friends and family as soon as each lockdown restriction ceases.  

Social homeostasis in marketing strategies 

Interestingly, social homeostatic circuity is present in our daily lives too, not just in situations of extreme survival, A good example of this is social marketing, through which businesses build human connections with their customers. Only those organisations or social media platforms that are able to maintain a dynamic equilibrium with their clients achieve long-term success. In this model of social homeostasis, the basic principles remain the same as that of biological homeostasis, however the mechanisms are slightly different. Here, the receptor mechanism would be surveys, social media, and other modes of interaction whereby a business can gauge the needs of its customers. This information reaches the central hub – Service Response Team (SRT) – who then dissect and analyse the information gathered. The final component is the effector, through which the business will employ certain strategies which send signals to their clientele that their suggestions have been implemented in practise. 

While we have a long way to go before our world starts to feel “normal” again, we can rest assured knowing that our neural circuitry is doing its best to restore our social and emotional balance. As we take those brave first steps out of our front door into the new world that awaits us, it’s fascinating to know that there’s an evolutionary reasoning behind those jitters as well as those bursts of excitement. In the next five-to-ten years, once our ships have successfully crossed the tumultuous waters of this pandemic, we will be able to truly evaluate how much of an extraordinary warrior the human brain has been through it all. 

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