Lizbeth Benson and Nilam Ram
In ecological sciences, biodiversity is the dispersion of organisms across species and is used to describe the complexity of systems where species interact with each other and the environment. Some argue that biodiversity is important to cultivate and maintain because higher levels are indicative of health and resilience of the ecosystem. Because each species performs functional roles, more diverse ecosystems have greater capability to respond, maintain function, resist damage, and recover quickly from perturbations or disruptions. In the behavioral sciences, diversity-type constructs and metrics are being defined and operationalized across a variety of functional domains (socioemotional, self, cognitive, activities and environment, stress, and biological). Emodiversity, for instance, is the dispersion of an individual’s emotion experiences across emotion types (e.g., happy, anger, sad). Although not always explicitly labeled as such, many core propositions in lifespan developmental theory—such as differentiation, dedifferentiation, and integration—imply intraindividual change in diversity and/or interindividual differences in diversity. For example, socioemotional theories of aging suggest that as individuals get older, they increasingly self-select into more positive valence and low arousal emotion inducing experiences, which might suggest that diversity in positive and low arousal emotion experiences increases with age. When conceptualizing and studying diversity, important considerations include that diversity (a) provides a holistic representation of human systems, (b) differs in direction, interpretation, and linkages to other constructs such as health (c) exists at multiple scales, (d) is context-specific, and (e) is flexible to many study designs and data types. Additionally, there are also a variety of methodological considerations in study of diversity-type constructs including nuances pertaining theory-driven or data-driven approaches to choosing a metric. The relevance of diversity to a broad range of phenomena and the utility of biodiversity metrics for quantifying dispersion across categories in multivariate and/or repeated measures data suggests further use of biodiversity conceptualizations and methods in studies of lifespan development.
Li Chu, Yang Fang, Vivian Hiu-Ling Tsang, and Helene H. Fung
Cognitive processing of social and nonsocial information changes with age. These processes range from the ones that serve “mere” cognitive functions, such as recall strategies and reasoning, to those that serve functions that pertain to self-regulation and relating to others. However, aging and the development of social cognition unfold in different cultural contexts, which may assume distinct social norms and values. Thus, the resulting age-related differences in cognitive and social cognitive processes may differ across cultures. On the one hand, biological aging could render age-related differences in social cognition universal; on the other hand, culture may play a role in shaping some age-related differences. Indeed, many aspects of cognition and social cognition showed different age and culture interactions, and this makes the study of these phenomena more complex. Future aging research on social cognition should take cultural influences into consideration.
Christiane A. Hoppmann, Theresa Pauly, Victoria I. Michalowski, and Urs M. Nater
Everyday salivary cortisol is a popular biomarker that is uniquely suited to address key lifespan developmental questions. Specifically, it can be used to shed light on the time-varying situational characteristics that elicit acute stress responses as individuals navigate their everyday lives across the adult lifespan (intraindividual variability). It is also well suited to identify more stable personal characteristics that shape the way that individuals appraise and approach the stressors they encounter across different life phases (interindividual differences). And it is a useful tool to disentangle the mechanisms governing the complex interplay between situational and person-level processes involving multiple systems (gain-loss dynamics). Applications of this biomarker in areas of functioning that are core to lifespan developmental research include emotional experiences, social contextual factors, and cognition. Methodological considerations need to involve careful thought regarding sampling frames, potential confounding variables, and data screening procedures that are tailored to the research question at hand.
Psychoanalyst Erik Erikson was the first professional to describe and use the concept of ego identity in his writings on what constitutes healthy personality development for every individual over the course of the life span. Basic to Erikson’s view, as well as those of many later identity writers, is the understanding that identity enables one to move with purpose and direction in life, and with a sense of inner sameness and continuity over time and place. Erikson considered identity to be psychosocial in nature, formed by the intersection of individual biological and psychological capacities in combination with the opportunities and supports offered by one’s social context. Identity normally becomes a central issue of concern during adolescence, when decisions about future vocational, ideological, and relational issues need to be addressed; however, these key identity concerns often demand further reflection and revision during different phases of adult life as well. Identity, thus, is not something that one resolves once and for all at the end of adolescence, but rather identity may continue to evolve and change over the course of adult life too.
Following Erikson’s initial writings, subsequent theorists have laid different emphases on the role of the individual and the role of society in the identity formation process. One very popular elaboration of Erikson’s own writings on identity that retains a psychosocial focus is the identity status model of James Marcia. While Erikson had described one’s identity resolution as lying somewhere on a continuum between identity achievement and role confusion (and optimally located nearer the achievement end of the spectrum), Marcia defined four very different means by which one may approach identity-defining decisions: identity achievement (commitment following exploration), moratorium (exploration in process), foreclosure (commitment without exploration), and diffusion (no commitment with little or no exploration). These four approaches (or identity statuses) have, over many decades, been the focus of over 1,000 theoretical and research studies that have examined identity status antecedents, behavioral consequences, associated personality characteristics, patterns of interpersonal relations, and developmental forms of movement over time. A further field of study has focused on the implications for intervention that each identity status holds. Current research seeks both to refine the identity statuses and explore their dimensions further through narrative analysis.
David Bunce and Sarah Bauermeister
Intraindividual variability in the present context refers to the moment-to-moment variation in attentional or executive engagement over a given time period. Typically, it is measured using the response latencies collected across the trials of a behavioral neurocognitive task. In aging research, the measure has received a lot of recent interest as it may provide important insights into age-related cognitive decline and neuropathology as well as having potential as a neurocognitive assessment tool in healthcare settings. In the present chapter, we begin by reviewing the key empirical findings relating to age and intraindividual variability. Here, research shows that intraindividual variability increases with age and predicts a range of age-related outcomes including gait impairment, falls and errors more broadly, mild cognitive impairment, dementia, and mortality. Brain imaging research suggests that greater variability is associated with age-related or neuropathological changes to a frontal–cingulate–parietal network and that white matter compromise and dopamine depletion may be key underlying mechanisms. We then consider the cognitive and neurobiological theoretical underpinnings of the construct before providing a description of the various methods and metrics that have been used to compute measures of variability – reaction time cut-offs, raw and residualized intraindividual standard deviations, coefficient of variation, ex-Gaussian curve and fast Fourier transformation. A further section considers the range of neurocognitive tasks that have been used to assess intraindividual variability. Broadly, these tasks can be classified on a continuum of cognitive demands as psychomotor, executive control or higher-order cognitive tasks (e.g., episodic memory). Finally, we provide some pointers concerning the pressing issues that future research needs to address in the area. We conclude that the existing body of theoretical and empirical work underlines the potential of intraindividual reaction time variability measures as additions to the neuropsychological test batteries that are used in the early detection of a range of age-related neurocognitive disorders in healthcare settings.
Eric S. Cerino and Karen Hooker
Intraindividual variability (IIV) refers to short-term fluctuations that may be more rapid, and are often conceptualized as more reversible, than developmental change that unfolds over a longer period of time, such as years. As a feature of longitudinal data collected on micro timescales (i.e., seconds, minutes, days, or weeks), IIV can describe people, contexts, or general processes characterizing human development. In contrast to approaches that pool information across individuals and assess interindividual variability in a population (i.e., between-person variability), IIV is the focus of person-centered studies addressing how and when individuals change over time (i.e., within-person variability). Developmental psychologists interested in change and how and when it occurs, have devised research methods designed to examine intraindividual change (IIC) and interindividual differences in IIC. Dispersion, variability, inconsistency, time-structured IIV, and net IIV are distinct operationalizations of IIV that, depending on the number of measures, occasions, and time of measurement, reflect unique information about IIV in lifespan developmental domains of interest. Microlongitudinal and measurement-burst designs are two methodological approaches with intensive repeated measurement that provide a means by which various operationalizations of IIV can be accurately observed over an appropriate temporal frame to garner clearer understanding of the dynamic phenomenon under investigation. When methodological approaches are theoretically informed and the temporal frame and number of assessments align with the dynamic lifespan developmental phenomenon of interest, researchers gain greater precision in their observations of within-person variability and the extent to which these meaningful short-term fluctuations influence important domains of health and well-being. With technological advancements fueling enhanced methodologies and analytic approaches, IIV research will continue to be at the vanguard of pioneering designs for elucidating developmental change at the individual level and scaling it up to generalize to populations of interest.
Nicole D. Anderson
Healthy aging is accompanied by decrements in episodic memory and working memory. Significant efforts have therefore been made to augment episodic and working memory in healthy older adults. Two principal approaches toward memory rehabilitation adults are restorative approaches and compensatory approaches. Restorative approaches aim to repair the affected memory processes by repeated, adaptive practice (i.e., the trained task becomes more difficult as participants improve), and have focused on recollection training, associative memory training, object-location memory training, and working memory training. The majority of these restorative approaches have been proved to be efficacious, that is, participants improve on the trained task, and there is considerable evidence for maintenance of training effects weeks or months after the intervention is discontinued. Transfer of restorative training approaches has been more elusive and appears limited to other tasks relying on the same domains or processes. Compensatory approaches to memory strive to bypass the impairment by teaching people mnemonic and lifestyle strategies to bolster memory performance. Specific mnemonic strategy training approaches as well as multimodal compensatory approaches that combine strategy training with counseling about other factors that affect memory (e.g., memory self-efficacy, relaxation, exercise, and cognitive and social engagement) have demonstrated that older adults can learn new mnemonics and implement them to the benefit of memory performance, and can adjust their views and expectations about their memory to better cope with the changes that occur during healthy aging. Future work should focus on identifying the personal characteristics that predict who will benefit from training and on developing objective measures of the impact of memory rehabilitation on older adults’ everyday functioning.
Glyn C. Roberts, Christina G. L. Nerstad, and P. Nicolas Lemyre
Motivation is the largest single topic in psychology, with at least 32 theories that attempt to explain why people are or are not motivated to achieve. Within sport psychology research, there are a plethora of techniques of how to increase and sustain motivation (strategies to enhance agency beliefs, self-regulation, goal setting, and others). However, when explaining the conceptual undergirding of motivation in sport, the why of motivation, two theories predominate: Achievement Goal Theory (AGT) and Self-Determination Theory (SDT). Both theories predict the same outcomes, such as increased achievement striving, sustained behavior change, and perceptions of well-being, but they differ in why those outcomes occur. AGT assumes that individuals cognitively evaluate the competence demands and meaningfulness of the activity, and that those perceptions govern behavior. SDT assumes that individuals are driven by three basic needs, competence, autonomy, and relatedness, and the satisfaction of those needs govern behavior. The following discusses both theories and concludes that each has their strengths and weaknesses.
Sarah E. Hampson
Although the belief that personality is linked to health goes back at least to Greek and Roman times, the scientific study of these links began in earnest only during the last century. The field of psychosomatic medicine, which grew out of psychoanalysis, accepted that the body and the mind were closely connected. By the end of the 20th century, the widespread adoption of the five-factor model of personality and the availability of reliable and valid measures of personality traits transformed the study of personality and health. Of the five broad domains of personality (extraversion, agreeableness, conscientiousness, emotional stability, and intellect/openness), the most consistent findings in relation to health have been obtained for conscientiousness (i.e., hard-working, reliable, self-controlled). People who are more conscientious have better health and live longer lives than those who are less conscientious. These advantages are partly explained by the better health behaviors, good social relationships, and less stress that tend to characterize those who are more conscientious. The causal relation between personality and health may run in both directions; that is, personality influences health, and health influences personality. In addition to disease diagnoses and longevity, changes on biomarkers such as inflammation, cortisol activity, and cellular aging are increasingly used to chart health in relation to personality traits and to test explanatory models. Recognizing that both personality and health change over the life course has promoted longitudinal studies and a life-span approach to the study of personality and health.
Jarred Gallegos, Julie Lutz, Emma Katz, and Barry Edelstein
The assessment of older adults is quite challenging in light of the many age-related physiological and metabolic changes, increased number of chronic diseases with potential psychiatric manifestations, the associated medications and their side effects, and the age-related changes in the presentation of common mental health problems and disorders. A biopsychosocial approach to assessment is particularly important for older adults due to the substantial interplay of biological, psychological, and social factors that collectively produce the clinical presentation faced by clinicians. An appreciation of age-related and non-normative changes in cognitive skills and sensory processes is particularly important both for planning the assessment process and the interpretation of findings. The assessment of older adults is unfortunately plagued by a paucity of age-appropriate assessment instruments, as most instruments have been developed with young adults. This paucity of age-appropriate assessment instruments is an impediment to reliable and valid assessment. Notwithstanding that caveat, comprehensive and valid assessment of older adults can be accomplished through an understanding of the interaction of age-related factors that influence the experience and presentation of psychiatric disorders, and an appreciation of the strengths and weaknesses of the assessment instruments that are used to achieve valid and reliable assessments.