If nothing else, 2020 has called attention to the role of immunity in every aspect of our lives. Improving and preserving immune health has become a core topic of conversation for politicians, healthcare providers, and business owners alike. It also colors our discussions with friends and family. But there’s so much more to the story than our susceptibility to COVID-19.
We now see that our individual patterns of immunity affect everything from our mood to our decisions. Interestingly, our immune function also seems to impact our relationships. The science here is blossoming, and when applied, may provide us with new tools to improve our interpersonal bonds.
Decades of scientific research have made it clear that the immune system does far more than just fight off infections. Immune cells and signals are key to our understanding of everything from cancer to heart disease to obesity. Additionally, there is a growing appreciation for the role of immunity in thinking and emotion. Disordered immunity, as represented by elevated inflammation, has been strongly associated with depression. High levels of inflammation have also been linked to worsened cognition, both in the short and the long term.
As it relates to our relationships, these effects on our mood and cognitive state are obviously a big deal. But the connection between immunity and our interpersonal bonds is even more intriguing. Recent research suggests that elevated inflammation induces social withdrawal and fosters a sense of social disconnection. Observations like these illuminate the possibility of a direct path from imbalanced immunity to poor relationships.
If altered immunity leads to social withdrawal, then it’s not surprising to see social isolation associated with a dramatic elevation in inflammatory markers. But some data also indicate that the opposite could also be true. Could isolation lead to inflammation? This hypothesis was investigated in a study from 2014. In this research, children who experienced more social isolation in childhood had higher levels of an inflammatory marker called C-reactive protein in their blood nearly 40 years later. These types of findings are also seen in older adults, in which social engagement correlates with lower levels of this same protein. The idea that social isolation can damage our immunity needs to be carefully considered in at a time of widespread social distancing policies.
The biological pathways linking immune function and our relationships are the subject of active research. In this conversation, the effects of stress are especially noteworthy. Stress has known links to both our interpersonal interactions and our immune function. An interesting review looked at the link between stress and loneliness, finding that higher levels of loneliness are associated with atypical reactions to stress. Of course, chronic stress also creates a number of problems more directly. These include outcomes that damage our chances of healthy relationships, like more trouble regulating negative emotion. One of the ways this happens may be through stress’s effect on our immune function. Chronic stress is thought to directly compromise our immunity, increasing inflammation while decreasing our immune resilience.
Another mechanism connecting immunity and our social interactions may involve dopamine, a neurotransmitter known to play a major role in shaping our behavior. Research primarily in animals demonstrates that dopamine signaling in the brain affects immune signaling. Additionally, inflammation may itself damage dopamine neurons.
Finally, for healthy relationships, we need empathy. It turns out that there may be crosstalk between the immune system and empathy. Specifically, immunity seems to be related to cognitive empathy—the ability to see things from someone else’s perspective. This was demonstrated in a 2019 paper in which elevated levels of the inflammatory marker C-reactive peptide predicted lower levels of cognitive empathy.
In summary, we now understand that there are bidirectional interactions between our interpersonal relationships and our immune system. An unbalanced immune system, and especially an inflamed state, appears to influence our brain function, contributing to feelings of social isolation as well as other mental states that may compromise our interactions with others. Similarly, the quality of our relationships may influence the health of our immune system.
To put this into context, now is a time when problems with our immunity and the health of our relationships are more important than ever. While it’s certainly important that we consider the typical interventions to improve immunity—including a healthy diet, adequate sleep, and regular exercise, we should also consider investing in better relationships as a way to promote better immune function. As it relates to our social lives, understanding the nuances of our immunity provides us with a new way of approaching our behavior, cognition, emotions, and subsequently, our relationships.