Loneliness Across the Life Span

Abstract

Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the current review, we provide a life-span perspective on one component of the evolutionary theory of loneliness-a component we refer to as the reaffiliation motive (RAM). The RAM represents the motivation to reconnect with others that is triggered by perceived social isolation. Loneliness is often a transient experience because the RAM leads to reconnection, but sometimes this motivation can fail, leading to prolonged loneliness. We review evidence of how aspects of the RAM change across development and how these aspects can fail for different reasons across the life span. We conclude with a discussion of age-appropriate interventions that may help to alleviate prolonged loneliness.
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Perspectives on Psychological Science
2015, Vol. 10(2) 250 –264
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DOI: 10.1177/1745691615568999
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Most people have experienced loneliness at some point
in their lives. For some people, it is a prolonged and
painful experience, with deleterious effects on mental
and physical health (S. Cacioppo, Grippo, London,
Goossens, & Cacioppo, 2015, this issue; Van Dulmen &
Goossens, 2013). For most people, however, loneliness is
a transient experience without long-lasting negative con-
sequences. According to the evolutionary theory of lone-
liness (J. T. Cacioppo etal., 2015, this issue), loneliness is
usually transient in nature because the aversive feelings
associated with loneliness motivate individuals to recon-
nect with other people. For simplicity, we refer to this
aspect of the evolutionary model as the reaffiliation
motive (RAM).
The RAM is thought to consist of three component
processes that promote reconnection. First is the aversive
feeling of loneliness, which evolved to signal to people
that their connections were broken or under threat and
motivated attention to their maintenance or repair (J. T.
Cacioppo, Cacioppo, & Boomsma, 2014; J. T. Cacioppo
et al., 2006). Second, the awareness that one is lonely
activates the behavioral reaffiliation process, which
causes people to withdraw from social situations
(Gardner, Pickett, Jefferis, & Knowles, 2005; Pickett &
Gardner, 2005; also see J. T. Cacioppo etal., 2015). Third,
loneliness has been proposed to increase implicit vigi-
lance for social threat (J. T. Cacioppo & Hawkley, 2009;
J.T. Cacioppo etal., 2015). When these component pro-
cesses of the RAM work well, they promote the develop-
ment of salutary relationships with others ( J. T. Cacioppo
& Hawkley, 2005; J. T. Cacioppo etal., 2006; Gardner
etal., 2005; Masi, Chen, Hawkley, & Cacioppo, 2011).
Our review of the ontogeny of loneliness is organized
around three questions regarding the RAM. First, how do
the environmental triggers of loneliness differ across the
life span? Second, how are maturational and develop-
mental risk factors for loneliness related to the RAM?
Finally, what are the implications of these developmental
568999PPSXXX10.1177/1745691615568999Qualter et al.Loneliness Across the Life Span
research-article2015
Corresponding Author:
Pamela Qualter, School of Psychology, University of Central
Lancashire, Fylde Road, Darwin Building, Preston, Lancashire, PR1
2HE, United Kingdom
E-mail: PQualter@uclan.ac.uk
Loneliness Across the Life Span
Pamela Qualter1, Janne Vanhalst2,3, Rebecca Harris4, Eeske
Van Roekel5, Gerine Lodder6, Munirah Bangee1, Marlies Maes2,
and Maaike Verhagen6
1School of Psychology, University of Central Lancashire, United Kingdom; 2School Psychology and
Child and Adolescent Development, KU Leuven - University of Leuven, Belgium; 3Research Foundation
Flanders, Belgium; 4Department of Education and Psychology, University of Bolton, United Kingdom;
5Interdisciplinary Center Psychopathology and Emotion Regulation, University Medical Center, University
of Groningen, The Netherlands; and 6Behavioural Science Institute, Radboud University, Nijmegen, The
Netherlands
Abstract
Most people have experienced loneliness and have been able to overcome it to reconnect with other people. In the
current review, we provide a life-span perspective on one component of the evolutionary theory of loneliness—a
component we refer to as the reaffiliation motive (RAM). The RAM represents the motivation to reconnect with others
that is triggered by perceived social isolation. Loneliness is often a transient experience because the RAM leads to
reconnection, but sometimes this motivation can fail, leading to prolonged loneliness. We review evidence of how
aspects of the RAM change across development and how these aspects can fail for different reasons across the life
span. We conclude with a discussion of age-appropriate interventions that may help to alleviate prolonged loneliness.
Keywords
loneliness, affiliation, development, prevalence, life span, hypervigilance, social withdrawal, evolutionary mechanism
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Loneliness Across the Life Span 251
aspects of the RAM for intervention when loneliness
becomes prolonged? On the basis of evidence presented,
we propose a strategy for the development of interven-
tions in which attention biases and behavior that accom-
pany prolonged loneliness at specific stages in
development are targeted. Table 1 summarizes the main
conclusions of each step in this article. Figure 1 illustrates
the component processes of the RAM and shows how
this mechanism might fail, promoting prolonged loneli-
ness across development.
Sources of Transient and Prolonged
Feelings of Loneliness Across
Ontogeny
The need to affiliate with others has been demonstrated
across the life span (Baumeister & Leary, 1995), with
loneliness being reported by people of different ages
(Heinrich & Gullone, 2006). However, differences exist in
sources of loneliness at different ages, and these differ-
ences are associated with changes in belonging needs
evidenced across ontogeny (Parkhurst & Hopmeyer,
1999). In Table 1, we present an overview of these devel-
opmental changes in the source of loneliness.
One of the first sources of loneliness is peer friend-
ship. In early childhood, forming and maintaining friend-
ships are mainly based on characteristics such as
proximity and sharing common activities, but throughout
childhood, the quality of friendships becomes increas-
ingly important. Children move from simply wanting to
be physically close to others to wanting close friendships
that are characterized by validation, understanding, self-
disclosure, and empathy (Bigelow, 1977; Parker & Asher,
1993). Expectations about friendship quality continue to
develop throughout adolescence and young adulthood,
with an increasing focus on intimacy (Buhrmester, 1990;
Steinberg & Morris, 2001). Thus, whereas friendship
quantity may be more important in predicting loneliness
in young childhood, friendship quality appears to be
more important in late childhood and adolescence.
A second important source of loneliness is the peer
group. In early childhood, belonging to a peer group
does not seem to be a main concern (Parkhurst &
Hopmeyer, 1999), although extreme signs of peer exclu-
sion such as peer victimization have been linked to lone-
liness in kindergarteners (Kochenderfer-Ladd & Wardrop,
2001). As they age, children become increasingly aware
and concerned about being accepted by the peer group,
and peer rejection is related to feelings of loneliness in
childhood (Gifford-Smith & Brownell, 2003). By adoles-
cence, concerns about one’s standing within the social
group increase (Crone & Dahl, 2012). Adolescents want
to be liked by a close friend, but they also have a desire
to be liked by the whole peer group. Indeed, lacking
friends, low friendship quality, peer rejection, and victim-
ization are all predictors of loneliness in adolescence
(Vanhalst, Luyckx, & Goossens, 2014).
Later in adolescence and during young adulthood, the
focus on social status decreases, but the need for intimate
friendships is maintained. Moreover, a third important
source of loneliness—romantic relationships—is increas-
ingly valued (Collins, Welsh, & Furman, 2009). Over the
course of adolescence, romantic experiences become
more normative, and the quality of one’s romantic rela-
tionship becomes increasingly important (Dush & Amato,
2005). During this stage in social development, there is a
move from simply wanting a romantic partner to wanting
a committed, high-quality romantic relationship. For
example, analyses of intact and broken-up relationships
in college revealed that relational satisfaction was associ-
ated with lower levels of loneliness, whereas relational
disappointment was associated with higher levels of
loneliness (Flora & Segrin, 2000). Marital status continues
to predict loneliness throughout adulthood (Diener,
Gohm, Suh, & Oishi, 2000), but marital quality is superior
to marriage per se in explaining individual differences in
loneliness (Hawkley etal., 2008). In older age, a number
of specific risk factors for loneliness emerge; these factors
pose challenges to established romantic relationships,
such as losing a partner, reduced social activities because
of increased physical disability and poor health (Dykstra,
Van Tilburg, & De Jong Gierveld, 2005), and being con-
fronted with a partner’s increasing frailty (Dykstra etal.,
2005).
Table 1 shows how there are substantial changes in
people’s social experiences and expectations across
development. These changes increase the likelihood of
social disconnection and opportunities for reconnection
in specific ways. When these changes in the social envi-
ronment are also accompanied by major physical and
psychological developmental shifts, researchers have
found the highest loneliness prevalence rates. Specifically,
the percentage of people feeling lonely “sometimes” or
“often” is highest during adolescence when youths enter
puberty and are faced with the challenge of establishing
their own identity; however, this percentage is also high-
est during old age when there is increasing frailty and
decreased mobility accompanied by the loss of loved
ones. The percentage of people reporting feeling lonely
“sometimes” or “often” is estimated to be less than 20% of
children 7–12 years of age (Bartels, Cacioppo, Hudziak,
& Boomsma, 2008), between 20% and 71% of late adoles-
cents and young adults (Brennan, 1982; Hawthorne,
2008; Rönkä, Rautio, Koiranen, Sunnari, & Taanila, 2014),
between 11% and 30% of middle-age adults (Dykstra
etal., 2005; Griffin, 2010; Hawthorne, 2008), and between
40% and 50% of adults older than 80 years of age
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252
Table 1. Loneliness Across Ontogeny: Source and Prevalence of Loneliness, Evidence for Components of the Reaffiliation Motive (RAM), and Appropriate Interventions
Stage of
development
Age range
in years
Belonging
needs
Sources of
loneliness
Prevalence
of people
feeling lonely
“sometimes”
or “often”
Components of the RAM
Negative thinking
that affects the
success of the
RAM
Proposed intervention
Evidence of
motivation to
reconnect
Evidence for
vigilance to
social cues
Evidence
for social
withdrawal
Young childhood 3–7 Shared fun
activities
Lack of a play
partner,
victimization
Children
>5 years
offer valid
definitions of
loneliness.
Shyness,
withdrawn
behavior
Distrusting
others, low self-
worth
They discuss
aversive
feelings, such
as sadness,
and ways to
cope with
loneliness
by making
contact with
others.
Middle–late
childhood
7–12 Allies,
confidants,
sense of
being liked
by a close
friend
Lack of a
close friend,
victimization by
the peer group,
peer rejection
20% ✓Difficulty
disengaging
from visually
presented
rejection stimuli;
sensitive to signs
of rejection,
fear, negative
evaluations
Shyness,
withdrawn
behavior
Maladaptive
attribution
style
(attribution
of control to
external loci),
distrusting
others, low
self-worth
Attention reprogramming:
Highlight important
aspects of social
scenes and enable
disengagement from
social threat stimuli
to aid reconnection.
Priming acceptance to
promote reconnection.
Retraining negative
thoughts: Addressing
counterproductive
attitudes and negative
thoughts (external, loci
of control, low trust
beliefs, low self-worth).
(continued)
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253
Stage of
development
Age range
in years
Belonging
needs
Sources of
loneliness
Prevalence
of people
feeling lonely
“sometimes”
or “often”
Components of the RAM
Negative thinking
that affects the
success of the
RAM
Proposed intervention
Evidence of
motivation to
reconnect
Evidence for
vigilance to
social cues
Evidence
for social
withdrawal
Early adolescence 12–15 Acceptance by
peer group
Lack of a
close friend,
nonacceptance
by peer
group/clique,
victimization
11%–20% ✓More reactive
to social
environment;
increased
responses to
both positive
and negative
environments;
sensitive to signs
of rejection, fear,
and negative
evaluations
Passivity
in social
interactions
and
withdrawn
behavior
Maladaptive
attribution
style
(attribution
of control to
external loci),
distrusting
others, low
self-worth,
anxiety
Attention reprogramming:
Coping with social
threat, noting important
aspects of social scenes
and use of information
to direct behavior
change. Priming
acceptance to promote
reconnection.
Retraining negative
thoughts: Addressing
counterproductive
attitudes and negative
thoughts (external loci
of control, low trust
beliefs, low self-worth).
Inclusion of tasks to
address anxiety around
reconnection.
Late adolescence/
young adulthood
15–21 Validation and
understanding
from a
close friend;
romantic
relations,
flirtations,
acceptance
as a possible
mate; marital
status
Lack of close
friend, lack
of romantic
relationship,
nonacceptance
as possible
mate
20%–71% ✓Remember more
social events;
visual cortex
activation greater
for unpleasant
social pictures
compared with
objects; enhanced
attention to
facial and vocal
expressions
of emotion;
sensitive to signs
of rejection, fear,
and negative
evaluations; initial
visual vigilance of
rejection stimuli
and attentional
avoidance
Withdrawn
behavior
Personality
traits, low
self-esteem,
anxiety, low
levels of trust
Attention reprogramming:
Coping with social
threat, noting important
aspects of social scenes
and use of information
to direct behavior
change. Priming
acceptance to promote
reconnection.
Retraining negative
thoughts: Addressing
counterproductive
attitudes and negative
thoughts (external loci of
control, low trust beliefs,
low self-worth).
Table 1. (continued)
(continued)
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254
Stage of
development
Age range
in years
Belonging
needs
Sources of
loneliness
Prevalence
of people
feeling lonely
“sometimes”
or “often”
Components of the RAM
Negative thinking
that affects the
success of the
RAM
Proposed intervention
Evidence of
motivation to
reconnect
Evidence for
vigilance to
social cues
Evidence
for social
withdrawal
Early and midlife
adulthood
21–50 Quality of
marital
relationship—
focus is on
intimacy
Lack of intimate
friendships
or romantic
relationship
11%–30% ✓Withdrawn
behavior,
passivity
in social
interactions
Maladaptive
attribution
style
(attribution
of control to
external loci)
Evidence of negative
thinking that may
reduce effectiveness
of the cognitive
reaffiliation motive in
early adulthood. The
behavioral reaffiliation
process appears to
work as in other stages.
Cognitive retraining
and cognitive behavior
therapy are effective.
Need to conduct studies
in which the cognitive
reaffiliation mechanisms
are examined to ensure
that these intervention
strategies are age
appropriate.
Mature adulthood
and old age
50+ Marital
quality—focus
on intimacy
and life
partnership
Lack of intimate
friendships
or romantic
relationship;
loss of a
partner in
old age and
ill-health
from mature
adulthood
onward;
reduced social
activities
40%–50% ✓Withdrawn
behavior
Lack of
perceived
control,
attribution
style
(attribution
of control to
external loci)
No examination of
cognitive reaffiliation
process, but the
behavioral reaffiliation
process appears to work
in the same way as in
other stages. Negative
thinking influences
prolonged loneliness
in the same way as in
other stages. Cognitive
retraining and cognitive
behavior therapy have
also been shown to be
effective.
Note: The check mark indicates age groups that also discussed aversive feelings such as sadness when describing loneliness. They also discussed ways to overcome loneliness and referenced
the need to reconnect with other people.
Table 1. (continued)
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Loneliness Across the Life Span 255
(Demakakos, Nunn, & Nazroo, 2006; Dykstra etal., 2005;
Victor, Scambler, Bowling, & Bond, 2005).
In addition to the normative changes in sources and
prevalence across development, there appears to be a
small subgroup of people who are at risk for prolonged
feelings of loneliness; such people are not identified in
analyses in which the mean levels of loneliness are the
focus. This subgroup consists of individuals who report
persistent loneliness over many years and report feeling
socially or emotionally distant from others. In several
multiwave longitudinal studies, researchers investigating
developmental trajectories of loneliness from childhood
through early adulthood have indicated that between 3%
and 22% of people experience prolonged loneliness
(Benner, 2011; Harris, Qualter, & Robinson, 2013; Jobe-
Shields, Cohen, & Parra, 2011; Ladd & Ettekal, 2013;
Qualter, Brown, etal., 2013; Schinka, Van Dulmen, Mata,
Bossarte, & Swahn, 2013; Vanhalst, Goossens, etal., 2013;
Vanhalst, Rassart, etal., 2013). Further, despite a dearth of
studies in which researchers investigated prolonged
loneliness in middle adulthood, stability and change in
loneliness among older adults have been investigated by
researchers using retrospective and longitudinal designs.
Evidence suggests that 15%–25% of older adults experi-
ence social or emotional isolation from others for many
months or years (Cohen-Mansfield, Shmotkin, &
Goldberg, 2009; Dykstra etal., 2005; Jylhä, 2004; Newall,
Chipperfield, & Bailis, 2013; Victor etal., 2005). In all of
these studies, those individuals following a trajectory of
high stable or increasing loneliness showed relatively
poor mental and physical health.
We next turn to the aspects of RAM that vary across
development. From an evolutionary perspective, loneli-
ness itself is not problematic at any age any more than is
hunger, thirst, or pain. Similar motivational, behavioral,
and cognitive processes may, therefore, be observed dur-
ing transient periods of loneliness across the life span as
long as the RAM is effectively leading to social reconnec-
tion. However, faulty RAM components across the life
span may contribute to individuals falling into the depths
of prolonged loneliness.
Motivation to Reconnect Across
Ontogeny
In 1953, Sullivan argued that loneliness was a strong
motivational force across development. J. T. Cacioppo
etal. (2006) posited that just as physical pain is an aver-
sive signal that evolved to motivate a person to take
action to minimize damage to one’s physical body,
Perceived social
isolation
Reaffiliation motive
activated–Motivated
to reconnect
Behavioral re-
affiliation process
activated: Withdrawal
from initial social
interaction
Cognitive reaffiliation
process activated:
Hypervigilance for
social cues to monitor
social situations and
possible social threat
Regulate behavior to
reconnect
Reconnection
Overattentiveness of
social cues/negative
interpretation of social
information
Behavioral
confirmation and
further social
withdrawal
More negative affect
Fig. 1. The activation of the reaffiliation motive (RAM). The highlighted “perceived social isolation” box is the starting point of the process. The
figure shows how RAM works for transient and prolonged loneliness. Prolonged loneliness is associated with negative cognitive biases, which
affect RAM during the cognitive reaffiliation process. Negative cognitive biases mean that social cues are viewed or interpreted negatively, eliciting
behaviors from others that confirm the lonely person’s perceptions and feelings of disconnection. This leads to further withdrawal and engagement
in a self-reinforcing loop as described by J. T. Cacioppo and Hawkley (2009), which leads to increasing feelings of loneliness. The model shows that
exit from the RAM comes at the point of hypervigilance and social monitoring, in which intervention could lead an individual who has previously
experienced prolonged loneliness to make appropriate behavioral changes and reconnect with others.
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256 Qualter et al.
loneliness is an aversive state that motivates a person to
minimize damage to one’s social body. Empirical evi-
dence supports that claim and shows that this motivation
is evident across human development.
Loneliness is viewed as an aversive state across the life
span, with children as young as 5 years of age offering
valid definitions of loneliness and discussing the associ-
ated aversive feelings, such as sadness and aloneness
(Cassidy & Asher, 1992). School-age children also discuss
the various interpersonal contexts associated with loneli-
ness, including loss, temporary absence, and psychologi-
cal distance (Hymel, Tarulli, Hayden Thomson, &
Terrell-Deutsch, 1999). Children aged 5 years and older
have clear ways of coping with loneliness, reporting the
need to make contact with others (Besevegis & Galanaki,
2010; Qualter, 2003; Qualter & Munn, 2002). Such descrip-
tions of loneliness are comparable with definitions
offered by adults (Jones, Cavert, Snider, & Bruce, 1985;
Rokach, 1989; Weiss, 1973). Together, these studies show
that loneliness appears to motivate people across ontog-
eny to reconnect with others.
Earlier in this review, we noted that there are different
sources of loneliness across development and a change
in focus from quantity of relationships to the quality of
those relationships. These changes mean that people
often find themselves unsure of their social environment
and unsafe because they do not know whom they can
trust or confide in. Thus, although it appears to be the
case that loneliness motivates even young children to
attend and seek connection with other people, it also
appears that loneliness can lead to other behaviors,
including increased withdrawal and attention to social
threat. These behaviors are discussed later (also see J. T.
Cacioppo etal., 2015).
The behavioral reaffiliation process
across ontogeny
According to the RAM, the aversiveness of loneliness
motivates people to withdraw from social encounters.
On first thought, such behavior seems odd, as withdraw-
ing is likely to evoke even greater loneliness. However,
withdrawing allows the next link in the mechanism—the
cognitive reaffiliation process—to work effectively: By
withdrawing from immediate social encounters, people
are able to assess the level of threat and determine
whether they need to find other ways of behaving to
reaffiliate with others (J. T. Cacioppo & Hawkley, 2009;
Gardner etal., 2005). There is evidence to support the
thesis that lonely people across ontogeny (and across
phylogeny; see J. T. Cacioppo etal., 2015) display social
withdrawal (see Table 1).
Empirical studies show that lonely adults are often
more withdrawn than their nonlonely peers (Watson &
Nesdale, 2012), avoid others (Nurmi, Toivonen, Salmela-
Aro, & Eronen, 1997), and are more passive in social
interactions (Jones, Hobbs, & Hockenbury, 1982). Cross-
sectional and experimental research in which loneliness
was induced showed that transient loneliness was associ-
ated with higher levels of shyness and fear of negative
evaluation (J. T. Cacioppo etal., 2006). Similar behavioral
profiles have been found for children and adolescents,
with higher loneliness associated with higher levels of
shyness and withdrawn behavior during social engage-
ment (Cassidy & Asher, 1992; Qualter & Munn, 2002;
Qualter, Rotenberg, etal., 2013; Rotenberg, 1994).
Although immediate, limited social withdrawal may be
generally adaptive because a person is able to observe
and then make judgments about appropriate social
engagement, general and prolonged social withdrawal
limits opportunities for social reconnection and can pro-
mote prolonged loneliness (Jobe-Shields etal., 2011). In
addition, children who experience prolonged loneliness
and who become increasingly withdrawn limit their
opportunities to practice their social interaction skills,
becoming more deficient in social skills over time
(Schinka etal., 2013). Figure 1 shows how social with-
drawal might work as part of RAM but also how it might
lead to problems with reconnection.
The cognitive reaffiliation process
across ontogeny
Activation of the RAM increases people’s attention to
social stimuli to promote reconnection to other people.
Evidence from adult studies demonstrates increased vigi-
lance to social cues in lonely people. In Table 1, we pro-
vide an overview of these findings, which shows that
loneliness in (young) adulthood is associated with
remembering more social events (Gardner etal., 2005),
enhanced attention to facial and vocal expressions of
emotion (Gardner et al., 2005; Pickett, Gardner, &
Knowles, 2004), greater activation of the visual cortex in
response to unpleasant social pictures of people com-
pared with objects (J. T. Cacioppo, Norris, Decety,
Monteleone, & Nusbaum, 2009), initial visual vigilance to
pictures depicting social rejection (Bangee, Harris,
Bridges, Rotenberg, & Qualter, 2014), and sensitivity to
signs of rejection and fear of negative evaluation (Jackson,
2007; Watson & Nesdale, 2012). Studies with lonely chil-
dren and adolescents have shown them to have difficulty
disengaging from rejection stimuli during an eye-tracker
task (Qualter, Rotenberg, et al., 2013) and have high-
lighted their sensitivity to signs of rejection (Jackson,
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Loneliness Across the Life Span 257
2007; Qualter, Rotenberg, et al., 2013). Further, results
from experience-sampling studies of early adolescents in
which researchers examined the responses of lonely
individuals to the social context showed that lonely indi-
viduals were more reactive to the social environment,
with increased responses to both positive and negative
environments (Van Roekel et al., 2013; Van Roekel,
Scholte, Engels, Goossens, & Verhagen, in press).
Overall, eye-tracking studies with lonely adults and
lonely children suggest an increased vigilance to social
threat, even though the presentation is different. For
example, whereas lonely children had difficulty disen-
gaging from social threat stimuli, lonely young adults dis-
played only an initial vigilance to social threat stimuli,
which can be explained by developmental changes in
attention processing. The initial vigilance pattern of pro-
cessing is thought to be automatic, unintentional, and
outside voluntary control, whereas the later stages of
attention are thought to be strategic, intentional, and
under voluntary control (Cisler & Koster, 2010). This
means the latter stages are influenced by developmental
changes in cognitive processing, particularly the reloca-
tion of attention (Casey, Galvan, & Hare, 2005) and per-
spective taking (Blakemore, 2008). Thus, differences in
attention processing of social threat information between
lonely children and lonely adults could be explained by
typical changes in information processing across ontog-
eny and by implicit versus explicit attentional processes
in adults (J. T. Cacioppo etal., 2015).
The eye-tracker studies by Qualter, Rotenberg, etal.
(2013) and Bangee et al. (2014) show that very lonely
children are having trouble disengaging, but very lonely
young adults have a practiced avoidance of social threat.
It is possible that the short initial vigilance to the social
threat is long enough for adults to gather social informa-
tion to then use to reconnect, but this may not be the
case, with lonely young adults actually avoiding the
social threat information. These differences may be
explained by typical changes in information processing,
but prospective research is needed to determine whether
these differences represent a developmental change that
reflects the emergence of problems with the innate
mechanism being considered here. It is possible that
when a person experiences failed attempts at reconnec-
tion across childhood and adolescence, the basic vigi-
lance system becomes calibrated away from social
information over time; this then limits future reconnec-
tion. It may also be the case that vigilance is affected by
developmental changes in executive functioning that
enable an individual to redirect his or her attention to
manage aversive emotions at the cost of attending to con-
textual information in the social environment that would
promote reconnection. Such notions must be tested in
future empirical work because of the implications for
interventions.
Individual differences that affect the
RAM
Multiple studies with children, adolescents, and adults
have shown that some lonely people differ from their
nonlonely peers in the ways that they interpret social
encounters and deal with difficulties in relationships.
These negative interpretations have often been consid-
ered to be part of the cognitive component of the RAM.
However, longitudinal research shows, instead, that they
determine the effectiveness and efficiency of the RAM by
influencing the interpretation of information gathered
during the operation of the cognitive component of the
RAM or because they affect approach-oriented behavior.
This evidence is more in line with the evolutionary model
of loneliness (see J. T. Cacioppo etal., 2015) and the find-
ing that people who experience prolonged loneliness
tend to form more negative social impressions of others.
Evidence suggests that loneliness is related to more
negative interpretations of the behavior of others as well
as to an underestimation of the social standing and social
abilities of others. This occurs in childhood and adoles-
cence (Qualter & Munn, 2002; Vanhalst, Luyckx, Scholte,
Engels, & Goossens, 2013) as well as adulthood (Duck,
Pond, & Leatham, 1994; Jones, Freemon, & Goswick,
1981; Jones, Sansone, & Heim, 1983). Further, lonely peo-
ple are low in trust for others (Rotenberg, 2010), and they
have specific attribution styles that are not conducive to
change (J. T. Cacioppo etal., 2000; Crick & Ladd, 1993;
Moore & Schultz, 1983; Nurmi et al., 1997; Qualter &
Munn, 2002; Renshaw & Brown, 1993). These findings
from cross-sectional studies support the idea that loneli-
ness is often associated with cognitive biases that pro-
mote negative thinking. Currently, there is no study
examining whether these negative thoughts are a direct
result of implicit increases in social vigilance as an out-
come of loneliness or lead to loneliness. However, there
is evidence that they promote prolonged loneliness.
Table 1 summarizes findings from prospective studies
of loneliness that show that maladaptive cognitive biases
(e.g., distrusting others) put children at heightened risk
for an increasing and stable high loneliness trajectory
(Qualter, Brown, etal., 2013). Further, several intraper-
sonal factors, such as low self-worth and personality
traits (e.g., introversion and emotional instability), have
been found to predict prolonged loneliness across child-
hood, adolescence, and adulthood (Dykstra etal., 2005;
Newall etal., 2013; Qualter, Brown, etal., 2013; Vanhalst,
Goossens, etal., 2013). Low self-worth, low trust of oth-
ers, and the attribution of control to external loci appear
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258 Qualter et al.
to be maintaining and exacerbating factors of loneliness
across ontogeny, perhaps because they provide a foun-
dation for the belief that loneliness cannot be remedied
(Laursen & Hartl, 2013; Qualter, Brown, et al., 2013).
Thus, it is possible that when the RAM is activated by
lonely people with low self-worth, low trust of others,
and external loci of control, negative thinking that hin-
ders reconnection increases; such negative thinking then
influences the interpretations of social information gath-
ered from the cognitive reaffiliation process and leads to
prolonged loneliness. This explanation offers some ideas
for future intervention strategies that are discussed in S.
Cacioppo etal. (2015) and that we return to later.
Prospective studies have also shown that there may be
biological and genetic influences on the effectiveness of
the RAM (see Goossens etal., 2015, this issue). For exam-
ple, prolonged loneliness is associated with genes that
are linked to faulty cognitive and attention processing,
including those related to sensitivity to emotional or
social information (5-HTTLPR: Beevers, Wells, Ellis, &
McGeary, 2009; OXTR: Theodoridou, Rowe, Penton-
Voak, & Rogers, 2009) as well as those related to atten-
tional control, reward sensitivity, and working memory
(DRD2: Cohen, Young, Baek, Kessler, & Ranganath, 2005;
Gelao etal., 2014). Goossens etal. argued that people
with a specific genetic variant may act in ways to create
circumstances that make them more lonely: They may be
less trusting of others and less prosocial, making social
reconnection more difficult. Thus, although it is impor-
tant that lonely people increase their surveillance of neg-
ative social cues in the social environment to reconnect
with others, certain individual differences (e.g., low self-
worth, certain attribution styles, personality traits) and
genetic profiles make some people overly sensitive to
emotional and social information, which may lead to
increased feelings of loneliness over time.
Intervention Strategies Across
Ontogeny That Address Faults in the
RAM
In this review, we have pointed to ways in which the
processes involved in the RAM might contribute to pro-
longed loneliness. In this section, we use that knowledge
to argue for certain prevention programs and interven-
tions in which the changing presentation of the RAM
across ontogeny is considered.
Attention retraining and priming
acceptance
Earlier, we discussed the presentation of the cognitive
reaffiliation process and how it was characterized by
different patterns of visual processing across ontogeny.
We discussed the fact that lonely children had difficulty
disengaging from social threat, but lonely young adults
appeared to show a practiced attentional avoidance of
the same social threat stimuli. These differences could
represent a developmental change that reflects the emer-
gence of a problem in the RAM: During childhood, the
focus on social threat may be adaptive because it moti-
vates children to reconnect and provides clues about
how to reengage, but avoidance of social threat informa-
tion among lonely young adults may indicate a tendency
to disconnect from the self and emotions in socially
threatening situations. This difference in visual attention
processing between children and adolescents (a) may be
the outcome of improved cognitive skills that enable
adults to redirect attention away from threatening infor-
mation or (2) may happen for adults who as children and
adolescents had intact RAM and who used the RAM to
attempt reconnection but failed, with the vigilance sys-
tem being regulated away from social information. In
future longitudinal work, researchers should examine
these developmental changes in more detail. If this pro-
cess is correct and the developmental changes reflect an
emergence of a problem with RAM, both prevention pro-
grams and interventions can be proposed. We offer some
suggestions here.
The finding that loneliness is associated with failure to
disengage from social threatening information during
childhood could be targeted for prevention or interven-
tion if it is found that such heightened vigilance does not
promote reconnection. Prevention programs could teach
all children what to focus on in social environments so
that they gather contextual information that can be used
to direct changes in behavior and thought as well as to
facilitate reconnection with others. Promoting social and
emotional competence generally, with an effective cur-
riculum (Greenberg, Kusche, Cook, & Quamma, 1995),
might prove successful, but a focus on contextual infor-
mation that can influence reconnection may be especially
effective. Researchers using such an approach could tar-
get lonely children for attentional training by using tasks
that elicit selective attention to social threat (e.g., emo-
tional faces or dot-probe tasks; Koster, Crombez,
Verschuere, & De Houwer, 2004; Norman, Lawrence, Iles,
Benattayallah, & Karl, 2014). We would expect this type
of intervention to prove successful for lonely children
who also have high levels of anxiety surrounding
reconnection.
Interventions could also be offered to lonely adults to
help them redirect their attention to social information
that could be used to guide interpersonal behavior and to
motivate them to reconnect. Indeed, interventions
designed to accentuate the social gains and positive social
features in the environment (e.g., a promotion-focused
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Loneliness Across the Life Span 259
mind-set) have been shown to be successful in increasing
reaffiliation (Lucas, Knowles, Gardner, Molden, & Jefferis,
2010). Further, such interventions have been shown to
modulate amygdala reactivity to threat (Norman et al.,
2014), suggesting that priming acceptance changes brain
functioning. Table 1 shows how attention retraining (pro-
gramming) and priming acceptance would be different
for different age groups on the basis of the currently
available empirical findings.
It is possible that the priming of social acceptance
increases social reconnection because it corrects a faulty
RAM. Tests of this hypothesis are needed because they
may provide new foci for intervention. Researchers of
such studies should utilize eye-tracking technology to
examine visual attention, but they should also use brain-
imaging techniques to elucidate different attention pro-
files and amygdala reactivity to social threat for lonely
people at different developmental stages. Findings from
such studies will help to further inform appropriate
intervention.
These attention retraining and priming interventions
may also be effective for people who have a genetic pro-
file (e.g., the less efficient variant of the serotonin trans-
porter gene; see Goossens etal., 2015) that could result
in overattention to potential social threat when aversive
feelings associated with loneliness are activated. Attention
retraining could be recommended for such people
because it redirects their attention to useful social infor-
mation and retrains the brain’s response to social threat.
There may be some strengths to having this specific
genetic profile that could also be utilized in an interven-
tion. For example, the serotonin transporter gene
increases vigilance to social threat, but it also increases
interpersonal sensitivity (Fiedorowicz et al., 2007) and
shows strong associations with social support and mood
state (Kaufman et al., 2004; Van Roekel et al., 2010).
Those findings suggest that the building blocks for suc-
cessful relationships are in place, which should mean
that priming acceptance is likely to be successful at cor-
recting the faulty RAM and reestablishing connection
with others.
Cognitive behavior therapy (CBT)
Earlier, we highlighted the fact that negative thinking
influences the effectiveness of the RAM, and increases
the risk of prolonged loneliness. Thus, we would expect
interventions that address maladaptive social cognitions
to be effective in helping people who experience pro-
longed loneliness. That hypothesis has found empirical
support, with a meta-analysis of loneliness interventions
showing that the programs targeting maladaptive social
cognitions were the most effective at reducing feelings of
loneliness (Masi etal., 2011; also see S. Cacioppo etal.,
2015). The meta-analysis included few interventions of
that kind for lonely children and none for lonely adoles-
cents; however, on the basis of the evidence presented in
this article that negative thinking can cause the RAM to
fail across ontogeny, we propose that interventions tar-
geting maladaptive social cognitions are likely to be
effective across development. Thus, CBT offers an inter-
vention that helps lonely people across ontogeny become
aware of counterproductive attitudes and negative
thought patterns that hinder reconnection. Table 1 shows
that the focus of these negative thoughts will be on dif-
ferent social relationships that depend on the develop-
ment stage. This means that CBT designed to help lonely
people should focus on specific sources of loneliness at
each developmental stage. Evidence that changes in the
perception of control can reduce loneliness over time in
an older adult population (Newall etal., 2013) by chang-
ing how that attitude is expressed through behavior sup-
ports the idea that changing cognitions leads to
reconnection via changes in behavior. This approach
would also help people who have intact RAM but who
feel anxious about reconnection and who show increas-
ing withdrawn behavior.
Increasing opportunities for social
interaction
Within the literature on loneliness, there is the argument
that increasing social contact and opportunities for social
reconnection could reduce loneliness (Qualter, 2003),
but reviews (S. Cacioppo, 2015; Masi etal., 2011) provide
strong empirical evidence that there are no significant
effects of such interventions. However, that literature is
limited to specific age groups and does not distinguish
between lonely people who experience transient versus
prolonged loneliness. Without randomized control trials,
researchers do not know whether interventions that aim
to reduce social isolation and increase opportunities for
reconnection are useful for certain lonely groups. Specific
groups of lonely people that might benefit from such
interventions, but for whom empirical data are not avail-
able, are those who are unable to reconnect because
they have few opportunities to engage with others.
Summary of interventions
In this section, we discussed both prevention programs
and targeted interventions for people with prolonged
loneliness. Meta-analyses in which depression was exam-
ined indicate that targeted intervention programs may be
more effective than universal prevention programs, with
the latter showing very small to no effects (Horowitz &
Garber, 2006; Merry etal., 2011). These findings should
be considered when designing programs to help lonely
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260 Qualter et al.
people, and they have informed our choice of recom-
mended programs across ontogeny: When we felt a pre-
vention program could have impact, we made proposals
for that; however, when we felt there was an individual
risk factor that needed to be targeted, we suggested a
targeted intervention approach. We were also conscious
of the fact that prevention work is easier in schools in
which all children or adolescents are brought together,
and we have been mindful of research that shows the
negative effects of being identified for intervention pro-
grams (Evans, Scourfield, & Murphy, 2014). Prevention
work is, of course, very difficult after individuals exit the
school and university systems, suggesting that targeted
interventions may be more appropriate in adulthood.
Conclusions and Future Directions in
Loneliness Research
In the current article, we have provided a life-span per-
spective on one of the components of the evolutionary
theory of loneliness, the RAM, which includes the aversive
feelings of loneliness that activate the behavioral and cog-
nitive reaffiliation processes. We have reviewed evidence
that the cognitive reaffiliation process may become faulty
when lonely people have certain intrapersonal character-
istics or are in social environments that make them
hypervigilant to social threats, creating a self-reinforcing
loop (J. T. Cacioppo & Hawkley, 2009) and that includes
increased withdrawal and prolonged loneliness. However,
there is no empirical work documenting whether and
when an adaptive heightened orientation to social cues
turns maladaptive. There is also no study that shows how
the cognitive reaffiliation process actually affects behavior
or whether behavior change is a separate parallel reaffili-
ation process that is also affected by individual differ-
ences. Thus, there is a need for researchers to examine
both transient and prolonged loneliness in future work
and to investigate the prospective associations among the
components of the RAM using longitudinal designs. We
believe that this represents a major overarching direction
for future research on loneliness across ontogeny.
What does a faulty RAM component
look like?
With the absence of longitudinal work, it is difficult to
establish whether the attentional avoidance shown by very
lonely adults (Bangee etal., 2014) is a practiced avoidance
strategy that helps people with prolonged loneliness cope
with perceived threat instead of a typical presentation of
this reaffiliation process. In future longitudinal research,
investigators should examine (a) whether there are
changes in the presentation of the cognitive reaffiliation
process that accompany changes in cognitive development,
(b) what characterizes an adaptive versus faulty cognitive
reaffiliation process across development (i.e., is transient
loneliness presented as a certain type of increased vigi-
lance, but prolonged loneliness as disengagement diffi-
culty or practiced avoidance depending on stage of
development?), and (c) why this adaptive process for reaf-
filiation fails to work at different stages of development.
In addition, although there is evidence from prospec-
tive research that negative thinking (e.g., general mistrust
and external loci of control) influences the maintenance
of, or increase in, loneliness, researchers know little
about how such biases influence the component pro-
cesses of the RAM. The use of experimental cognitive
paradigms, observational methods, and prospective
designs in those studies will be important. Table 1 shows
the need to also examine the cognitive reaffiliation pro-
cess in middle adulthood and old age so that researchers
can examine whether there are changes in the presenta-
tion of this mechanism at later stages of development.
Gender differences in loneliness
It is unclear whether there are gender differences in lone-
liness or whether the RAM works differently for male and
female individuals. In recent studies, researchers who
examined gender differences in the stability of loneliness
produced mixed results (Benner, 2011; Harris etal., 2013;
Newall, Chipperfield, & Ballis, 2013; Qualter, Brown,
etal., 2013; Vanhalst, Goossens, etal., 2013; Van Roekel
et al., 2013); researchers who examined the cognitive
biases and behavior of lonely people have typically not
examined gender differences or produced mixed find-
ings (Heinrich & Gullone, 2006). This is also the case
with researchers who have examined the cognitive reaf-
filiation process. If aversive feelings of loneliness moti-
vate people to reconnect and activate the RAM as well as
its behavioral and cognitive components, and this mech-
anism is seen across ontogeny, then there are unlikely to
be gender differences. However, there may be gender
differences in whether the component parts of the RAM
are successfully used, and there may be interactions with
specific intrapersonal factors. Thus, it is difficult to say
whether there are gender differences in transient loneli-
ness, whether gender influences the effects of loneliness
on cognitive biases and behavior, and whether such dif-
ferences vary across ontogeny. Thus, in future research
on loneliness, investigators need to make a concerted
effort to examine and report gender differences.
Cultural differences in loneliness
Even though loneliness appears to be a common experi-
ence across ontogeny, it is likely to be influenced by
cultural factors. Cultures may differ in their beliefs on the
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Loneliness Across the Life Span 261
virtues and purposes of time spent alone (Jones,
Carpenter, & Quintana, 1985) and on norms and expecta-
tions about relationships across the life span (Van Staden
& Coetzee, 2010). However, there is limited cross-cultural
research on loneliness (Hawkley, Gu, Luo, & Cacioppo,
2012) and no consensus regarding prevalence of loneli-
ness as a function of individualistic versus collectivistic
cultures (Chen etal., 2004). Cross-cultural studies should
also be conducted within a country to examine loneli-
ness in subcultures and minority groups (Van Staden &
Coetzee, 2010). In future studies, researchers should
examine whether there are differences in loneliness
across ontogeny as a function of culture, which means
that they need to establish the cultural equivalence of
child, adolescent, and adult loneliness measures.
Concluding Remarks
In sum, our review of the life-span literature indicates
that, despite differences in the sources of loneliness
across ontogeny, people of all ages are motivated to
reconnect with others. Also, behavioral (e.g., social with-
drawal) and cognitive (e.g., vigilance to social cues) reaf-
filiation processes are evident at different stages of
development. This review further indicates that the RAM
often goes awry and can lead to prolonged loneliness,
for example, when the component processes of the sys-
tem occur in combination with individual risk factors of
loneliness, such as self-defeating attributions, low self-
esteem, anxiety, certain personality traits, and certain
genetic vulnerabilities. On the basis of these conclusions,
we have proposed specific loneliness interventions for
different developmental stages, and we have outlined
avenues for future research. Given the harmful conse-
quences of loneliness for physical and psychological
health across the life span (J. T. Cacioppo & Hawkley,
2010; S. Cacioppo etal., 2015; Holt-Lunstad etal., 2015,
this issue; Van Dulmen, & Goossens, 2013), effective age-
appropriate interventions for loneliness may yield large
dividends across development.
Declaration of Conflicting Interests
The authors declared that they had no conflicts of interest with
respect to their authorship or the publication of this article.
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