Synonyms

Adaptive self; Age identity; Personal identity; Possible selves; Self-concept; Self-construal; Self-continuity; Self-definition; Self-esteem; Self-regulation; Self-representation; Views of self

Definition

The self is a cognitive structure that involves representations and evaluation of an individual’s past, present, and future (Brandtstädter and Greve 1994; Diehl et al. 2011). The structure of the self is typically described along three dimensions (Asendorpf and van Aken 2003): A content dimension that involves context-related and domain-specific knowledge of one’s internal states, motives, and behaviors. The contents of self-knowledge are also described with respect to their verifiability and veracity (i.e., realistic or illusionary) (Baltes 1997). A temporal dimension that reflects knowledge about one’s past or future self, and about change of the self over time (Bluck and Alea 2008). An evaluative dimension that reflects emotional responses to one’s self-representation. In addition, there is a debate regarding whether the self in adulthood should be defined as a process (i.e., regulating one’s thoughts and actions), or whether the self reflects an outcome of the aging process. Structures of the aging self are defined as outcomes of age-related change, while the self also involves processes that regulate age-related change. Theories of personal identity in old age often do not differentiate between structures and processes in the formation or maintenance of identity across adulthood. In this vein, maintaining a sense of personal identity across adulthood and continuity of identity typically involves effort in response to a change or to discontinuity in the aging process.

Introduction

This entry focuses on two pertinent issues in the literature on self and identity across adulthood.

  1. (A)

    What is the structure of the aging self? How stable is the aging self?

  2. (B)

    What are the regulatory functions of the self across adulthood?

The first issue addresses the contents and the structure of the self across adulthood as an outcome of aging-related challenges. Typically, the structure and stability of the aging self involves information-processing, temporal, and affective components. The second issue addresses the regulatory self as a process across adulthood. The process of self-regulation pertains to the pursuit of goals, to the accomplishment of developmental tasks, and to the maintenance of continuity or stability. At present, the theoretical and empirical research on self-regulation in the aging process remains vague with respect to whether the regulatory self is the target (i.e., regulating one’s internal states), or the origin of regulatory efforts (i.e., producing a cognitive, affective, or behavioral output). Much of the literature pertains to the regulatory self in the latter perspective, while the first perspective is sometimes referred to as coping, or as emotion regulation. There exists a plethora of theoretical and empirical work on self-representations across adulthood (Brandtstädter 1999; Diehl et al. 2011). Consequently, and for reasons of parsimony, this entry focuses on the self across adulthood from a lifespan psychology perspective with regard to the following five fundamental principles of development (Baltes 1997):

  • First, the aging process typically entails not only loss but also gains until very late in life. The aging self entails a changing ratio of loss and gain experiences across adulthood. More importantly, the meaning of what is a gain and loss is malleable. Any loss experience may be subjectively construed as reflecting or involving an experience of gain, or of personal growth. For example, coping with a severe health problem may also entail a sense of mastery and control (Heckhausen 1999).

  • Second, there is a multidimensionality of change across adulthood. That is, aging-related change in one domain of functioning may differ from change in another domain. For example, how one perceives oneself in professional life may differ from how one develops in the context of family life. Such domains of the self may be differentially interrelated across adulthood depending on age. Accordingly, self-representations show considerable domain specificity, and domain-specific changes in old age (Diehl et al. 2011; Freund and Ebner 2005).

  • Third, there is much behavioral and cognitive plasticity across adulthood, even very late in life. Individuals are able to learn and develop new knowledge, skills, and behaviors at all phases of adulthood. Consequently, there is also malleability of the aging self that appears to respond in flexible and adaptive ways to contextual changes in old age (Brandtstädter 1999).

  • Fourth, the course and direction of the aging process depends on social and cultural contexts (Baltes 1997). For example, findings of research on age differences in interdependent versus independent self-construal in various cultures suggest that with increasing age, there is an increasing correspondence between cultural values and an individual’s self-representation as a member of the culture (Diehl et al. 2011). For example, older adults in China tend to show a more interdependent self-construal, while older adults in the US tend to promote values that reflect stronger independent self-construal (Fung 2013).

  • Fifth, the human lifespan reflects a finitude of personal resources, and involves a limited future lifetime. Thus, individual differences in resources and remaining time in life strongly impact the course, direction, and outcome of one’s development across adulthood (Carstensen 2006; Heckhausen 1999; Lang et al. 2011). Accordingly, the aging self may positively adapt to a shrinking of one’s remaining time in life and to limited resources in old age. Even when experiencing much physical and psychological change, many older adults manage to maintain a sense of continuity of self and identity throughout the aging process, and even into very late life. There is robust evidence that when confronted with the finitude of life, and with limited resources, the regulatory self displays flexibility, resilience, and malleability that contributes to experiences of continuity, or even stability of the self (Brandtstädter 1999; Carstensen 2006).

The Structure of the Aging Self: Stability and Change Across Adulthood

A fundamental distinction in the structure of the self pertains to the duality of the self as agent (“I”) versus the self as known (“Me”) in the tradition of the works by William James (James et al. 1890). In the “self as agent”-perspective, the term self typically reflects the origin or target of an individual’s conscious thought or action. Examples of this perspective pertain to concepts such as self-regulation or self-monitoring. In the “self as known” perspective, the self pertains to contents that account for a person’s self-representation. The terms self, self-concept, views of self, and self-representation are used interchangeably to reflect the self-as-known perspective. Mostly, the structure of the self is described along three major dimensions: (Asendorpf and van Aken 2003) a content dimension (e.g., “Who am I?”), (Baltes 1997) a temporal dimension (e.g., “How did I change? How shall I change?”), and (Bluck and Alea 2008) an affective or evaluative dimension (e.g., “How satisfied am I with myself?”). Such dimensions are strongly interrelated. Evaluation of the self typically occurs in a temporal frame involving one’s past and future, while reflecting domain-specific and contextual contents. These dimensions of the self operate jointly to both stabilize the self and to promote continuity of personal identity across adulthood (Brandtstädter and Greve 1994; Diehl et al. 2011; Troll and Skaff 1997). Accordingly, a critical question is to what extent the stability and change in content, temporal, and affective dimensions of the self reflect age-related adaptation processes. Lastly, although the three dimensions of the aging self are closely connected in the representations of adults, it is not yet well understood how these dimensions work together to form an adaptive, resilient, and proactive self in old age (Brandtstädter 1999; Freund and Ebner 2005).

The Content of Self-Representations Across Adulthood

Representations of the self typically refer to a person’s knowledge about his or her attributes that he or she believes to be relevant or meaningful (Diehl et al. 2011; Filipp and Klauer 1986). This typically involves all aspects of an individual’s self-related knowledge, such as one’s physical appearance, personality, behavior, values, attitudes, and motives. The structure of such knowledge is embedded in an individual’s developmental context, thus reflecting individual differences related to cohort and chronological age. For example, there exist substantive age differences in self views: Older adults’ self views as compared to those of young adults’ are typically found to be made up of more issues related to current interests, life circumstances, health, and chronological age. Findings from such studies are corroborated in research on the contents of self-definitions that found much similarity in contents of self-definitions between old and very old adults (Diehl et al. 2011; Freund and Ebner 2005). Self-definitions in old age appear to reflect challenges and contexts of old age that revolve around issues of health, social roles, and meaningful activities in everyday life. Accordingly, it is a robust finding that a more flexible or multifaceted self-definition is often associated with more adaptive functional outcomes in late life (Brandtstädter 1999; Brandtstädter and Greve 1994; Diehl et al. 2011; Freund and Ebner 2005).

To date, few studies have examined the change in the contents of self views in old age from a longitudinal perspective, and those that have often provide data based on short time intervals only. Therefore, findings on the temporal stability of self-descriptions are not consistent and contradictory. There are several possible explanations to help explain the inconsistent findings regarding the stability and change of the aging self.

  1. (a)

    Findings vary depending on the measurement approach. For example, methods using a free response format show less stability than self-descriptive ratings (Diehl et al. 2011).

  2. (b)

    Context- or domain-specific self-knowledge (e.g., “I am quite amused about this new movie”) is different than universal self-descriptions (e.g., “I am a humorous person”) that are known to be shared by many individuals (Snyder and Shenkel 1975). Consequently, universal contents of self-definitions are likely to show greater stability over time. The self views of older adults may reflect greater domain-specificity and context-relatedness, and are thus less stable.

  3. (c)

    Core self-representations differ from surface knowledge about self (Asendorpf and van Aken 2003). While the core self reflects stable knowledge about one’s personality (e.g., related to Big Five personality traits), surface self-representations reflect contextual influences that may depend on specific tasks or activities. Accordingly, Diehl and colleagues (Diehl et al. 2011) report that temporal stability of the self is positively associated with a measure of perceived authenticity.

  4. (d)

    Veracity and verifiability of self-related knowledge may also affect stability and change. Some contents of self-definition may be more objectively testable (e.g., “I am a skilled lawyer”) when related to physical appearance, health, skills, competence, and cognitive abilities, while some contents of self-definitions are not observable or difficult to verify (e.g., “I am trustworthy”). This typically pertains to self-views of internal or past states of self, to motives, and to preferences. Typically, the contents of self-definition are not checked with regard to their veracity. Objectively testable views of the self (e.g., “I am intelligent”) may show greater stability because they are less context-specific. There may be aging-related shifts with regard to veracity of self-representations (e.g., becoming more accurate with age; 14).

In sum, findings on the stability and change of self-views in old age vary depending on what contents of the self are examined and on how such contents are assessed. More research is needed to explicitly address issues related to veracity, verifiability, idiosyncrasy, and context- and domain-specificity of self-representations across adulthood. In addition, multimethod measurement approaches are recommended in the assessment of self-representations across adulthood (Diehl et al. 2011).

The Temporal Dimension of the Aging Self

The passing of time is a central dimension in descriptions of the aging self. The temporal dimension of the self reflects adaptation, maintenance, and continuity of identity across adulthood. The passing of time in self has been described with concepts such as personal identity (Troll and Skaff 1997), autobiographical memory or remembered self (Bluck and Alea 2008), and possible selves (Hooker 1999). For example, an older person’s view of his or her current self may result from a reflection of his or her past (e.g., “I am wise now, and I learned many lessons in life”), his or her present (e.g., “I am as happy today as I was last year”), or from thoughts related to one’s future (e.g., “I feel old because there is not much left to do in life for me”). There is a paucity of integrative views on how the temporal components of the aging self relate to the structure and stability of the self. In general, findings suggest that the self-representations of older adults are mostly present-oriented, and more likely to refer to the past than to the future (Diehl et al. 2011; Filipp and Klauer 1986; Freund and Ebner 2005). It has also been suggested that this may be reflective of the narrowing of future time that results in a process of seeking meaning in those domains and contexts that are of immediate centrality and relevance of the self (Brandtstädter 1999; Carstensen 2006).

A critical issue pertains to the adaptive function of the temporal perspective in views of the self. There is agreement in the literature that the temporal perspective in self-representations serves to stabilize the present view of the self (Brandtstädter 1999; Staudinger et al. 2003). Temporal perspectives may contribute to such stabilization in several ways:

  1. (a)

    Comparing one’s current self with a less positive view of the self in the past (e.g., “I have become more wise now”). Such downward temporal comparisons may protect one’s current view of his or her self (Staudinger et al. 2003). One implication is that typically, with increasing age, the veracity in representations of one’s past self is difficult to prove.

  2. (b)

    Anticipating one’s future self in humble ways provides a positive frame of reference for views of the self in the future (e.g., “My life is much better than I had expected”; 14).

  3. (c)

    Focusing on one’s present internal state of self may provide a meaningful experience when perceiving a narrowing of one’s remaining time in life (Carstensen 2006).

In sum, the temporal perspective is critical for understanding the adaptivity, the plasticity, and the malleability of the aging self. The temporal perspective reflects one of the fundamental experiences that also relates to a flexibility of aging identity in old age (Weiss and Lang 2012). Accordingly, there may be two processes responsible for promoting a flexible aging identity, where one process is related to a dissociation of the self from one’s age group, and a second process pertains to one’s identification with his or her generation or birth cohort as a resource of social identity. In old age, perceiving one’s past self in terms of mastery and competence, while expecting one’s future in humble ways, and finding meaning in one’s current self appears to reflect a resilient and adaptive self (Lang et al. 2013).

The Evaluative Dimension of Aging Self

The emotional component of self-representations is reflected in positive and negative evaluations of the self. The evaluative dimension of the aging self is strongly associated with two psychological constructs, namely self-esteem (Wagner et al. 2014) and possible selves (Hooker 1999).

Self-esteem is defined as a positive evaluation of one’s self, and has been shown to decrease over time with respect to both mean levels, and rank-order stability (Wagner et al. 2014). Currently, it is an open issue to what extent the expression of self-esteem in old age depends on age-specific resources, where age-specific resources are not fully understood. For example, self-esteem in old age may depend more strongly on how well older adults manage to lower their expectations towards their future self. Developing more modest and prevention-oriented frames of self-evaluation may protect, and at times even provide a positive attitude toward the self in old age (Brandtstädter 1999).

Possible selves involve an evaluative frame of the self in the aging process. Hoped-for selves and feared selves reflect an individual’s strivings and goal-pursuits. That is, fears indicate what one wants to preserve and maintain, and hopes pertain to aspects of the self that one would like to change or achieve. In this vein, possible selves constitute a motivational dimension in the structure of the aging self (e.g., “What am I up for?”; 9). While hopes pertain to a striving for growth and goal achievement, feared selves reflect a preventive orientation, and strive to maintain the present state of self. Thus, hoped-for and feared selves may pertain to distinct processes in the evaluation of the aging self.

Generally, future expectations are robustly observed to be relatively low and modest among the oldest-old adults. Discrepancies between the ideal self and the current self are reported to be relatively low in old age (Diehl et al. 2011). It remains an open question as to what extent age-related changes in discrepancies of possible and current selves also reflect a positive or negative evaluation of the self. Theories of positive versus negative self-perceptions of aging are not always precise with regard to whether the positive or negative affective valence involves a unidimensional (i.e., bipolar), or a two-dimensional structure. In addition, the time perspective of affective evaluations of the self is still not well understood. Positive evaluations of one’s past self, one’s present self, and one’s future self may have age-differential functions (Brandtstädter and Greve 1994; Bluck and Alea 2008; Hooker 1999; Staudinger et al. 2003). Also, social comparisons with other people may age-differently influence one’s self-evaluation in old age (Heckhausen 1999). More research is needed to clarify the age-differential temporal dimensions of self-evaluation in the aging process. Finally, positive self-evaluation is robustly found to contribute to positive aging outcomes such as health and longevity (Wagner et al. 2014).

The Regulatory Self Across Adulthood: Adaptive Functions

In lifespan psychology, the individual is typically viewed as a co-producer of his or her own development (Baltes 1997). The notion of co-produced aging implies that there are active processes involved that reflect responses to age-related challenges such as limitation, loss, or environmental change. This implies that individuals engage in interactive processes between their internal states and the external world. Hence, individuals may either bring about a change of their internal self or a change in the external world. Processes of adapting the aging self as well as processes related to changing one’s contexts in the aging process are typically referred to as self-regulation or developmental self-regulation (Brandtstädter 1999; Heckhausen 1999). Regulation processes may differ depending on chronological age, available resources, and time limitations remaining in life. For example, studies show that individuals actively choose meaningful contexts and social roles across adulthood when they perceive to have limited time left in life (Carstensen 2006; Fung 2013). In this vein, individuals invest resources in activities and goal pursuits that they prioritize, while disengaging from other less prioritized domains of life.

Regulation of the aging self reflects age-associated efforts and activities that emerge in response to age-specific challenges across adulthood (Baltes 1997). Typically, challenges that require regulatory efforts involve limitations or constraints of the older individual’s resources. In the aging process, there are typically two main sources for an increased need of self-regulatory effort.

First, limitations of resources in old age, and the finitude of time in life both challenge self-representations in later adulthood. The biology of the aging organism typically relates to increased loss experience, declining health, and limited physical or mental functioning (Baltes 1997). In addition, only humans are capable of anticipating their future self and to perceive the ending of their time in life (Carstensen 2006; Lang et al. 2011). Thus, older adults are typically confronted with biological deterioration and with a nearing end of their lives. Taken together, these objective conditions of human existence can be expected to threaten or even erode the stability and continuity of the aging self. Surprisingly however this is not observed. Consequently, one may expect powerful and strong self-regulatory forces that contribute to the maintenance, continuity, and stability of the self until very late in life.

Second, in later adulthood compared to earlier phases of adulthood, there are fewer social norms that structure one’s activities, tasks, and social roles (Heckhausen 1999). At the same time, negative views of aging and age stereotypes prevail. However, in old age there is much heterogeneity and variability in all domains of functioning, including the self (Baltes 1997). Consequently, the potentials of the individual reflect a wide array of biographical, contextual, and biological resources. This implies that there do not exist general guidelines or rules on how challenges related to old age may be mastered in positive ways. Generally, there is not one uniform trajectory of change in old age; on the contrary, the course and direction of an individual’s aging process may strongly reflect a life-long history of individual decisions. Again, this involves that individuals may have to invest regulatory effort in response to challenges, but there is not one single solution on how to find an adaptive person-environment fit.

In sum, both biological and societal constraints challenge the plasticity and the malleability of the regulatory self in old age. There are several theoretical perspectives that have elaborated and advanced assumptions of processes involved in the adaptive regulation of the aging self. For reasons of space, two exemplary models of self-regulation in old age are addressed here: the dual-process-model of assimilation and accommodation of the resilient self (Brandtstädter 1999; Brandtstädter and Greve 1994), and the model of selective optimization with compensation (Baltes 1997; Lang et al. 2011). Descriptions of related models such as the life-span theory of primary and secondary control can be found elsewhere (Heckhausen 1999).

Dual-Process-Model of Assimilation and Accommodation

Throughout adulthood, individuals are confronted with processes of change of internal or external resources. Such aging-related change may result from discrepancies between the desired and the actual self in old age. According to the dual-process model, there are two ways of coping that individuals can utilize to reduce, resolve, or eliminate self-discrepancies in old age. These coping strategies are referred to as assimilation and accommodation processes (Brandtstädter 1999; Brandtstädter and Greve 1994), and are assumed to operate antagonistically, that is, when accommodative processes are activated, assimilative regulations are inhibited.

Assimilation involves intentions that aim to transform a situation such that the situation is in greater accordance with the individual’s self-representation or personal goals. Assimilative activities target the direction and regulation of one’s behavior, and pursuits that are of personal relevance to one’s self concept. Thus, assimilation involves activities that stand in the service of continuity of one’s self and identity. For example, according to the dual-process model, older adults may engage in assimilative actions that involve prevention of future self-discrepancies (e.g., preparatory activity), correction of ongoing behaviors (e.g., choosing a more healthy diet or engaging in sports), or compensation (e.g., use of a hearing aid). However, it is suggested that assimilative activities are relinquished when it is not in the service of self-continuity (Brandtstädter 1999).

Accommodation, in contrast, is activated when assimilative efforts are obstructed and when the continuity of self is challenged. Accommodation involves efforts to restructure and reframe one’s self-representation and goal pursuits, for example, by lowering expectations and restructuring priorities and preferences. Brandtstädter (Brandtstädter 1999) argued that the accomodative process – once activated – “overrides assimilative tendencies” (Brandtstädter 1999, p. 128) by eliminating and reinterpreting any prior thought or pursuit that is in the service of such tendencies. For example, when goals are blocked, one may disengage from, devalue, or redefine a goal in more flexible ways.

In addition, some depictions of the assimilation-accommodation model also refer to an additional process that has been suggested to protect the self from realizing any potential discrepancies between desired and actual states. This process has been described as immunization (Brandtstädter 1999; Brandtstädter and Greve 1994). Immunization involves a preconscious and automatic avoidance or neglect of self-discrepant information. It is not quite clear to what extent such immunization may be separated from automatic, unconscious self-regulation related to either assimilation or accommodation (Freund and Ebner 2005). Immunization may pertain to perceptual and attentional cognitive processes of the aging self. More empirical evidence is needed to better understand the specific ways in which immunization may be empirical differentiated from assimilative and accommodative processes.

Overall, the dual-process model posits that assimilation and accommodation contribute in fundamental ways to the continuity and to the positivity of self-representations in the aging process. While operating in antagonistic ways, all three processes are relevant to successfully adapt to the challenges of the aging process. There is robust empirical evidence that with increasing age, accommodative strategies such as flexible goal-adjustments prevail over more assimilative self-regulation strategies (e.g., tenacious goal pursuits). Moreover, it has been shown that a shift from an assimilative to an accommodative self-regulation is associated with more positive aging outcomes and psychological resilience (Brandtstädter 1999).

Self-Regulation Model of Selection, Optimization, and Compensation

The self-regulation model of selection, optimization, and compensation (SOC) reflects the multidimensionality of the developmental dynamics of gains and losses across adulthood (Baltes 1997). According to the model of SOC, any developmental process reflects the joint interplay of three fundamental principles, namely: selection, optimization, and compensation. These principles operate within and across all domains of behavior and cognition throughout the human life course. SOC principles furthermore substantively contribute to positive developmental outcomes (Baltes 1997; Lang et al. 2011), including the stability, continuity, and resilience of the aging self. All three principles (i.e., selection, optimization, and compensation) have been shown to be involved in adaptive self-regulatory processes of changing gain-loss dynamics across adulthood (Freund and Ebner 2005; Lang et al. 2011).

Selection involves choosing meaningful goals, tasks, or contexts in the aging process. This implies that any decision to pursue specific goals, tasks, or contexts involves gains (in the chosen domain) and losses in not chosen cognitive or behavioral domains. Generally, selection is a necessary developmental process because of limited life time and the finitude of resources. Thus, selection typically involves a narrowing of behavioral options over time.

Optimization pertains to the refinement, investment, or enhancement of resources to accomplish a goal or task in specific behavioral or cognitive domains. For example, individuals may invest their time and effort to improve their skills and abilities in a specific task. Optimization implies that costs of self-regulation are minimized while maximizing benefits.

The principle of compensation involves the substitution, repair, or restoration of resources in response to a loss or a limitation of the self. Compensation may occur in response to internal challenges to the self (e.g., memory decline), or in response to external challenges to the self (e.g., widowhood).

All together the three principles of selection, optimization, and compensation describe ways of how the self deals with internal and external challenges and opportunities in order to minimize loss while maximizing gains or growth experience. Thus, the SOC model involves an optimality criterion in the aging process. Optimality also refers to the concept of self-contentment in old age that may involve a focus on maintenance rather than a focus on personal growth or self-improvement.

The model of selection, optimization, and compensation is in accordance with assumptions of the dual-process model of assimilation and accommodation. Both models are embedded in a lifespan theoretical framework and build on fundamental principles of lifespan psychology. A difference between these models pertains to what is viewed as the salient motive that drives the regulatory effort of the aging self. The dual-process model emphasizes the effort of eliminating discrepancies between the desired and the actual self. Theories of selection, optimization, and compensation typically emphasize the ever-changing dynamics of gains and losses across adulthood as a central motive of regulatory effort that involves minimization of losses and maximization of gains (Baltes 1997; Freund and Ebner 2005). Therefore, the selection, optimization, and compensation model is explicit in addressing the fundament impact of internal and external resources that protect the flexibility, resilience, and malleability of the aging self. Once again, both models should be seen as complementing each other at different levels of analysis of self-regulatory processes across adulthood. While the processes of selection, optimization, and compensation more explicitly address the dynamic transactions between a person and their environment across all domains of functioning (including the self), the dual-process model underscores the steering function of the continuity and consistency of the self as a cognitive structure.

Conclusion

As people grow old, individuals typically show stability and continuity in the structure of their self-representations. The principles that contribute to the stabilization and stability of the aging self have been reported to be associated with an adaptive choice of contents of one’s self concept, with an adaptive use of temporal perspectives regarding one’s past, present, and future, as well as with self-serving selection of evaluative information about one’s self. Taken together, the stability and continuity of self-representations may reflect a powerful psychological and cognitive adaptation of the human mind that functionally operates even in the face of dramatic loss and health decline until very late in life.

Findings providing evidence for the robustness, and the resilience of the aging self have generated a wealth of theoretical accounts on the underlying psychological mechanisms of such stabilization processes (Brandtstädter 1999; Brandtstädter and Greve 1994; Carstensen 2006; Freund and Ebner 2005; Heckhausen 1999). Such mechanisms of self-stabilization typically represent two broad classes of self-regulation: The first class targets internal states of the self, and the second class targets executive functions of the self directed at the external world. Internal self-regulation involves psychological adaptations such as adjusting one’s expectations, disengaging from goals, or restructuring one’s priorities. Executive self-regulation pertains to mechanisms that are typically associated with investment of resources to improve or enhance one’s functioning such as physical exercises, cognitive training, choosing new friends, or soliciting help in a difficult life situation. Both types of regulatory efforts may complement each other in the process of stabilization of the self as people grow older.

Cross-References