Systems Thinking

Background & Literature Review

An Aging America

The United States is an aging nation. The number of adults aged 65 and older grew by a third from 2010 to 2020 and is expected to increase another 47 percent by 2050 (Mather & Scommegna, 2024). Older Americans are expected to comprise a larger share of the total population and outnumber children within the next decade. These demographic changes are associated with an increase in the average life expectancy, a decrease in the fertility rate, and the aging of the large baby boomer generation—all of whom will be 65 and older by 2030 (“The U.S.,” 2018).

A Lonely America

The Office of the Surgeon General (OSG) (2023) published a report detailing an “epidemic of loneliness” in the United States. Recent research suggests that over half of Americans experience some kind of loneliness (“The Loneliness Epidemic,” 2021). Another survey found that 1 in 5 Americans report always or often feeling lonely, and only a fifth of these respondents considered it a major problem (DiJulio et al., 2018). The prevalence of loneliness is alarming considering its detrimental health effects. According to the OSG report, rates of loneliness may be higher than rates of smoking, diabetes, and obesity, but only a fifth of Americans have heard or read about the problem “a lot.”

Nearly half of American respondents in the DiJulio et al. (2018) survey believed that loneliness is an individual problem (45%) rather than a public health problem (47%). Among British respondents, far more considered loneliness a public health problem (66%) than an individual one (27%). The majority of American respondents believed individuals and families (83%) should play a “major role” in reducing loneliness relative to the government (27%).

These findings suggest that Americans often attribute loneliness to personal shortcomings rather than societal or environmental issues. Further, the dangers of prolonged loneliness are not well established among the public or taken seriously.

Older adults are considered an at-risk group for social disconnection by the OSG report. Globally, younger adults report higher rates of loneliness than older adults (“The Global State,” 2023). This trend is present in the U.S., as rates of companionship and social engagement with friends sharply declined among 15-24 year olds over the past two decades. In the same time period, rates of companionship and social isolation increased among older adults (Kannan & Veazie, 2022).

This is the double-edged sword of social connection and aging: on one hand, older adults tend to socialize more and focus on emotionally meaningful relationships. On the other hand, older adults often experience shrinking networks and live in socially isolating environments.

Health Effects of Loneliness & Social Isolation

Loneliness is associated with an increased risk of negative physical and mental health effects, including coronary heart disease, stroke, dementia, depression, anxiety, and suicide (OSG, 2023).

Yang et al. (2016) found that establishing and maintaining social connections is most important for adolescents and older adults to reduce future health risks. This means that the groups with the highest risk of loneliness and social isolation are also at the highest risk of worsening their health when dealing with loneliness and social isolation. Yang et al. also identified a causal link between social connectedness in older adults and reduced rates of hypertension and obesity. While older adults naturally have a higher risk of developing chronic conditions, socially connected older adults are healthier and less at risk of diseases.

Holt-Lunstad (2017) presents a multitude of ways social connection can interact with health outcomes. Using the social ecological model, she considers social factors that affect health outcomes across the individual, relationship, community, and society levels. 

At the individual level, neurochemical mechanisms reward socializing and social support can buffer against stress. On the other hand, social rejection activates the same brain networks as physical pain. This alerts individuals to repair relationships to avoid or diminish the pain response, reinforcing the physiological importance of maintaining a robust social network.

Social baseline theory presents a similar argument on the importance of social connection. This theory contends that having and maintaining social relationships is a baseline for normal brain function, and lacking connection depletes resources by increasing cognitive and physiological effort. This resource depletion is addressed by either heavy energy investment or energy conservation, which can lead to acute or chronic distress and subsequent negative health outcomes (Coan & Sbarra, 2015). In other words, “the human brain is designed to assume that it is embedded within a relatively predictable social network characterized by familiarity, joint attention, shared goals, and interdependence” (Beckes & Coan, 2011, pp. 976-977).

At the relationship level, attachment in dyadic and close relationships has been linked to health behaviors and outcomes, such as in boosting emotion regulation by “reducing threat and increasing feelings of security, thereby blunting physiological reactivity” (Holt-Lunstad, 2017, p. 446). Close relationships may also affect cardiovascular, endocrine, and immune function. Additionally, early childhood is considered a sensitive period for social connection. Social isolation in early childhood has been linked to higher rates of C-reactive protein, “a reliable marker of inflammation associated with coronary heart disease, depression, and type 2 diabetes” (Holt-Lunstad, 2017, p. 446).

At the community level, built environment factors like walkability, community resources, traffic-induced stress, and neighborhood crime contribute to health behaviors and outcomes. Social contagion theory explains how health behaviors (e.g., obesity and smoking) and affective states (e.g., happiness and loneliness) travel through social networks. Christakis & Fowler (2013) found this effect for up to three degrees of connection—the health behaviors of our friend’s friend’s friend can influence our behaviors.

At the societal level, social and cultural norms and their effects on health behaviors must be considered. The continuum between individualistic and collectivist cultures is an important area of focus.

Structure, Function, & Quality of Connections

Holt-Lunstad (2021) identifies three characteristics of social connections that exist on a continuum. In this model, an increase in any characteristic of connection increases health protection, while a decrease in connection increases health risk (Figure 1).

Structure is concerned with the quantity of social connections and their roles. Function is concerned with how relationships fulfill social needs, regardless of whether social support is actual or perceived. In this case, social support consists of aid (e.g., help, advice, money), affect (e.g., emotional support, warmth, kindness), and affirmation (e.g., encouragement, validation of identity, beliefs, values). Quality is concerned with the positive or negative effect that social connections have on your life, irrespective of how many connections you have in total.

Figure 1. Social Connection Continuum (Holt-Lunstad, 2021)

Relationship Structure, Function, & Quality Throughout Life

The Convoy Model of Social Relations posits that people maintain a convoy of social relationships that moves with them throughout their lifetime (Antonucci et al., 2014). The convoy can expand or shrink as social ties strengthen or weaken. The convoy is also multi-dimensional; connections “vary in their closeness, their quality (e.g., positive, negative), their function (e.g., aid, affect, affirmation exchanges), and their structure (e.g., size, composition, contact frequency, geographic proximity)” (Antonucci et al., 2014, p. 84). The Model is typically depicted by three concentric circles grouping social connections into “close, closer, and closest” categories. High quality connections are located in one’s innermost circle, marking the people who are “closest” to you, whether that be family, friends, or a partner. These people are confidants that provide significant emotional, instrumental, and affirmative support.

The idea that connections can change in structure, function, and quality throughout the lifespan is integral to this body of research. As people get older, their total number of social connections tends to decrease (Bruine de Bruin et al., 2020). This makes sense considering middle-aged adults and older adults often experience the loss of loved ones, role intensification (e.g., professional, spousal, and parental roles that limit leisure time), and eventually the loss of roles (e.g., retirement, in which professional connections go away). Less time is dedicated to making connections as a middle-aged or older adult compared to teenagers and young adults.

Interestingly, this decline in social contacts mainly affects “peripheral” connections, or people from the middle or outer circles of your social convoy. Your inner circle—the number of close friends you have—stays relatively consistent throughout your lifetime (Figure 2) (Bruine de Bruin, et al., 2020; English & Carstensen, 2014).

Figure 2. Changes in Social Convoy and Total Network Over Lifespan (English & Carstensen, 2014)

The loss of peripheral contacts may not just be a natural process of losing loved ones and stepping away from societal roles, but an emotion regulation response. According to Socioemotional Selectivity Theory, older adults “prune” their social networks to focus on their most emotionally important relationships (Carstensen et al., 1999). This results from older adults’ cognitive appraisal of time—when someone believes their time is limited, their goals become more present-oriented and tend to focus on finding meaning and achieving emotional satisfaction. English and Carstensen (2014) argue that “among the best ways individuals can regulate their emotions is through strategic efforts to surround themselves with emotional, meaningful, and satisfying social partners.”

On the contrary, someone who perceives their time as unlimited may have future-oriented goals that prioritize investing in knowledge and experience accumulation. For younger people that have a lengthy “time horizon,” making peripheral connections can help in achieving future goals (e.g., networking). However, research generally suggests that the quality of one’s social connections is more important than the quantity.

Loneliness, Social Isolation, & Social Connectedness

This research project is concerned with loneliness and social isolation in older adults. First, it is important to distinguish between these similar but different concepts. De Jong-Gierveld & Havens (2004) define these terms well:

Loneliness is characterized by the unpleasant feeling of lacking certain relationships or missing a certain level of quality in one’s contacts with other people. Loneliness concerns the manner in which individuals perceive, experience, and evaluate the lack of communication with other people. Social isolation concerns the objective characteristics of the situation individuals are confronted with and refers to shortcomings in the size of their network of social relationships (p. 110).

The key difference is that loneliness is a subjective measure while social isolation is objective. Much of the literature on this topic uses loneliness as an outcome variable because it is easy for participants to self-rate using tested scales (e.g., UCLA 3-Item or de Jong-Gierveld Loneliness Scale). 

It is also possible for someone to feel lonely without experiencing social isolation, and vice versa. For example, one can have a small social network but feel a sense of belonging and connectedness. On the other hand, someone with many friends can struggle with loneliness or “feel lonely in a crowded room.” Because an objective measure of social isolation is not always telling of how people feel, this paper primarily focuses on measures of social connectedness (Figure 1) and loneliness.

For this Master’s Project, I developed a systems map that summarizes various predictors of social connectedness in older adults and interactions between these predictors. Existing work has compiled these findings (see “Social Isolation,” 2020), but no one has conceptualized social connectedness in older adults using a systems thinking approach. My model builds off the Holt-Lunstad (2018) systems model for social connection, using relationship structure, function, and quality as the primary determinants of social connectedness in older adults. Given that much of the literature is concerned with factors that predict loneliness, this model assumes that loneliness is a lack of social connection.

Systems Model Key Determinants & Relationships

Coming soon…

References

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