Lizbeth Benson and Nilam Ram
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Psychology. Please check back later for the full article.
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. Typically, higher biodiversity is indicative of health and resilience of the ecosystem because each species performs functional roles, which means the ecosystem has greater capability to respond, maintain function, resist damage, and recover quickly from perturbations or disruptions. In behavioral sciences, diversity-type constructs and metrics are being used to describe a broad range of psychological, social, behavioral, physical and environmental phenomena. 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. 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.
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.
Gerben J. Westerhof and Susanne Wurm
Aging is often associated with inevitable biological decline. Yet research suggests that subjective aging—the views that people have about their own age and aging—contributes to how long and healthy lives they will have. Subjective age and self-perceptions of aging are the two most studied aspects of subjective aging. Both have somewhat different theoretical origins, but they can be measured reliably. A total of 41 studies have been conducted that examined the longitudinal health effects of subjective age and self-perceptions of aging. Across a wide range of health indicators, these studies provide evidence for the longitudinal relation of subjective aging with health and longevity. Three pathways might explain this relation: physiological, behavioral, and psychological pathways. The evidence for behavioral pathways, particularly for health behaviors, is strongest, whereas only a few studies have examined physiological pathways. Studies focusing on psychological pathways have included a variety of mechanisms, ranging from control and developmental regulation to mental health. Given the increase in the number of older people worldwide, even a small positive change in subjective aging might come with a considerable societal impact in terms of health gains.
Working memory as a temporary buffer for cognitive processing is an essential part of the cognitive system. Its capacity and select aspects of its functioning are age sensitive, more so for spatial than verbal material. Assumed causes for this decline include a decline in cognitive resources (such as speed of processing), and/or a breakdown in basic control processes (resistance to interference, task coordination, memory updating, binding, and/or top-down control as inferred from neuroimaging data). Meta-analyses suggest that a decline in cognitive resources explains much more of the age-related variance in true working memory tasks than a breakdown in basic control processes, although the latter is highly implicated in tasks of passive storage. The age-related decline in working memory capacity has downstream effects on more complex aspects of cognition (episodic memory, spatial cognition, and reasoning ability). Working memory remains plastic in old age, and training in working memory and cognitive control processes yields near transfer effects, but little evidence for strong far transfer.