Right now we enjoy more ways to stay connected with people across the globe than at any time in history. What a remarkable irony, then, that “loneliness” is still a topic finding its way into headlines, perhaps now more than ever. How can oceans of distance no longer be an obstacle to communicating, and yet a third of us report being lonely in recent studies, and the number appears to be increasing?
University of Chicago neuroscientist John Cacioppo has dedicated his career to finding the answers. With co-author William Patrick, Cacioppo wrote the definitive book on the topic: Loneliness: Human Nature and the Need for Social Connection, which has set the stage for studying loneliness and its effects in a new light. Dr. Cacioppo recently spent some time discussing his research with David DiSalvo at Neuronarrative.
What originally interested you about loneliness as a field of study?
As a social species, we create emergent organizations beyond the individual – structures that range from dyads, families, and groups to cities, civilizations, and cultures. These emergent structures evolved hand in hand with neural and hormonal mechanisms to support them because the consequent social behaviors helped these organisms survive, reproduce, and care for offspring sufficiently long that they too survived to reproduce. To study the effects of social connection, we compared individuals who were socially connected with those who were socially isolated.
Humans are such meaning making creatures that we quickly determined that perceived social isolation was more critical in most instances than objective social isolation, so we compared people who felt they were socially isolated (i.e., lonely) with those who did not feel isolated (i.e., nonlonely). To be sure the effects we were finding were attributable to loneliness, we also performed experiments in which we randomly assign people to conditions that induce feelings of high or low loneliness, and we performed longitudinal studies to compare the effects on individuals when they felt lonely and when they did not feel lonely. Bill Patrick and I wrote Loneliness: Human Nature and the Need for Social Connectionbecause the results of this research suggested a very different view of human nature than the rugged, rational individualist we have seen championed for so long.
When most people think of loneliness, they think of someone sitting alone in a room with no one to talk to, leading to a stiff case of the blues. How different is your definition of loneliness from the popular conception?
Loneliness is the feeling of social isolation. Although being isolated from others may increase the likelihood of feeling lonely, being alone is not the same as feeling alone. Writers, for instance, spend a great deal of time alone but they may not feel alone because they have their colleagues, characters, and readers in mind as they work on the story. College freshman who leave family and friends for the first time to attend school, on the other hand, may be around more people at college than at home but they often feel socially isolated because they do not feel well connected to others.
What do we know about the effects of loneliness on the brain?
We now know quite a lot, though the full story is still unfolding. For instance, research suggests that social rejection and social pain are associated with the activation of some of the same regions of the brain that are active in physical pain. Using functional MRI, we recently found that there are at least two neural mechanisms differentiating social perception in lonely and nonlonely young adults. For pleasant depictions, lonely individuals appear to be less rewarded by social stimuli, as evidenced by weaker activation of the ventral striatum to pictures of people than of objects, whereas nonlonely individuals showed stronger activation of the ventral striatum to pictures of people than of objects.
These findings fit nicely with behavioral research showing that lonely individuals find pleasant daily social interactions to be less rewarding than nonlonely individuals. For unpleasant depictions, lonely individuals were characterized by greater activation of the visual cortex to pictures of people than of objects, consistent with their attention being drawn more to the distress of others, but nonlonely individuals showed greater activation of the TPJ, consistent with their reflecting less on their own perspective and more on the perspective of those in distress than lonely individuals. These findings help explain why lonely individuals can act in a more egocentric fashion than nonlonely individuals even though lonely individuals want to connect with others.
You recently presented at the American Association for the Advancement of Science annual meeting on compelling findings about links between loneliness and physiological problems. What were some of the most surprising of these findings?
The health implications of loneliness are really at the core of our recent book. We have found loneliness to be associated with heightened resistance to blood flow throughout the body; elevated blood pressure as one ages; heightened hypothalamic pituitary adrenocortical activity as indexed by higher morning levels of adrenocorticotropic hormone and larger rises in the stress hormone, cortisol, in the morning; less salubrious sleep; a diminished ability to exert self-control and avoid personal temptations; increased depressive symptomatology even when controlling for current depression; poorer health behaviors such diet and exercise; and higher allostatic load -peripheral biological markers of wear and tear on the body.
But the most surprising finding may be that loneliness is associated with altered gene expressions in the nucleus of immune cells, specifically with the under-expression of genes bearing anti-inflammatory glucocorticoid response elements (GREs) and over-expression of genes bearing response elements for pro-inflammatory NF-κB/Rel transcription factors. These effects may be mediated by the effects of loneliness on neuroendocrine activity, which in turn operates on the immune cells.
One revelation about loneliness to me is that it’s subject to genetic variation. How big a role does this play?
Loneliness is about 50% heritable, but this does not mean loneliness is determined by genes. An equal amount is due to situational factors. What appears to be heritable is the intensity of pain felt when one feels socially isolated. Being sensitive or insensitive are each fine, but what is important is to create a social environment that matches one’s predisposition toward feeling social pain. People who are sensitive to possible social disconnection tend to be lonelier more frequently or intensely than people who are relatively insensitive to social disconnection. Whether or not one is socially disconnected depends on the social context and the social world people create for themselves, however. If one is especially sensitive, then it may benefit one’s health and well being to prioritize the development and maintenance of a few high quality relationships.
In the next several years, do you see our society becoming more prone to loneliness or less? If more, is there anything we can do to straighten the course?
People interact with more people now than in the 20th century, and the distances at which people interact are greater than ever before. But loneliness is more strongly related to the quality than number of interactions, as anyone who has rushed by family members en route to a long traffic-congested commute to work can attest. We regard loneliness to be a biological construct, a state that has evolved as a signal to change behavior – very much like hunger, thirst, or physical pain – that serves to help one avoid damage and promote the transmission of genes to the gene pool. In the case of loneliness, the signal is a prompt to renew the connections we need to survive and prosper. Viewed in this way, loneliness – either ours or those of our friends and family – can signal us to re-prioritize how we are spending our time so that we can nurture our connections with those in our lives who are especially meaningful.
What are you working on now?
The dominant metaphor for the scientific study of the human mind during the latter half of the 20th century has been the computer – a solitary device with massive information processing capacities. Our studies of loneliness left us unsatisfied with this metaphor. Computers today are massively interconnected devices with capacities that extend far beyond the resident hardware and software of a solitary computer. It became apparent to us that the telereceptors of the human brain have provided wireless broadband interconnectivity to humans for millennia. Just as computers have capacities and processes that are transduced through but extend far beyond the hardware of a single computer, the human brain has evolved to promote social and cultural capacities and processes that are transduced through but that extend far beyond a solitary brain.
To understand the full capacity of humans, one needs to appreciate not only the memory and computational power of the brain but its capacity for representing, understanding, and connecting with other individuals. That is, one needs to recognize that we have evolved a powerful, meaning making social brain. This social brain is not always a benevolent brain, however. Our research certainly says humans have the capacity to be driven by ruthless competition and narrow self-interests, but it also shows that we have an additional, wondrous capacity to cooperate, care about others as well as oneself, and compete in fair and mutually beneficial ways. As a society, it may be important to find ways to promote the latter over the former in individuals. We are now seeking to gain a better understanding of the social brain and what sociocultural norms, rules, or sanctions promote collective actions that are appropriate for the problems we are facing in the 21st century.
Cacioppo, J., & Hawkley, L. (2003). Social Isolation and Health, with an Emphasis on Underlying Mechanisms Perspectives in Biology and Medicine, 46 (3) DOI: 10.1353/pbm.2003.0049
Hawkley, L., Masi, C., Berry, J., & Cacioppo, J. (2006). Loneliness Is a Unique Predictor of Age-Related Differences in Systolic Blood Pressure. Psychology and Aging, 21 (1), 152-164 DOI: 10.1037/0882-7922.214.171.124