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.
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.
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.
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.