The Overall Architecture of Lifespan Development - Essay Example

This research focuses on theory and research of lifespan developmental psychology. It outlines and analyses the perspectives on cultural andhuman development through different levels of analysis, these being predictions about general construction of lifespan ontogeny comprising of directionality and age-differential allocation of developmental resources which are categorized into three goals; These being those of growth, maintenance and the regulation of loss. To support the argument a meta-theory of development is crafted based on the composed and adaptive interplay between three processes of behavioral regulation: compensation optimization, and selection. INTRODUCTION Lifespan developmental psychology (LP) refers to the study of individual development (ontogenesis) from birth to old age (Neugarten 1996). It is a study of physical changes, emotional changes and perceptual changes of individuals over the span of life as they grow and interact with the environment. As individuals grow they are open to more and more opportunities of growth and learning till they reach old age where the process of growth of human mind as well as opportunities and the capacity to learn and grow more is compromised. The study initially focused on infants and children however over the period of time with the advancement in research and literature the horizons of lifespan development theory have broaden with formulation of theory for adults including adolescence, adult development and aging. An assumption of LP is that development is a lifelong process irrespective of the age with varying immersions in development example, maintenance, transformation, erosion in psychological structures, etc. Psychologists relating to this hold deduce that the overall ontogenesis of mind and behavior are mostly multifunctional, dynamic, nonlinear and multidimensional (Baltes 1997). Lifespan research and theory is projected to envision three components of human development inter-individual uniformities in development, inter-individual differences in development and intra-individual elasticity in development. Drawing attention towards the above mentioned aspects with respect to age differentials lay the foundation of the conceptual and methodological enterprise (Weinert & Perner 1996). Lifespan theory can be developed around person centered or function centered approaches. Person centric approach contemplates a person as a system by outlining the development of a person through a lifetime (Smith & Baltes 1997). While, function centric approach is less holistic in nature and selects a characteristic of a person which is evaluated through the development of a person through a lifetime example, personality type, responsiveness, etc. Lifespan developmental psychology is a theoretical framework developed by Tetens which encompasses both person and function centric approaches (Baltes & Goulet 1970). Since the inception of this field the German and the American/ European approaches had been contrasting with Germans banking on a more holistic approach while Americans focused on specialist breakdown based upon genetics, biology, age and a maturation- based concept of growth. However, American’s now have adopted the lifespan approach due to several environmental reasons such as new emerging fields like gerontology relating to lifelong signs of aging (Neugarten 1996), development in literature and theories, etc. Therefore, a holistic view of development through maturation with different circumstances is needed (Cairns 1998). THE OVERALL ARCHITECTURE OF LIFESPAN DEVELOPMENT While examining LP in particular detail the first level of analysis is the overall biological and cultural architecture (Baltes et al 1998) that is, with age closeness the value of culture is seen to be enhanced though its efficacy causes a decline in the relationship between biology, evolutionary process and culture functions. Evolutionary Selection Benefits As a person ages genes become less significant in the development process of a function this is when the genome and evolutionary process have a negative correlation (Finch 1996). However, in the case of reproductive fitness this does not hold true for which the first half of life or younger age is suitable. These findings remained hidden for years as earlier people had shorter life spans and death rate was high during the first half of life. It has now become evident that evolution in the second half of life has its repercussions with the aspect of aging (Martin et al 1996). Age-Related Increase in Need for Culture Human development has been made through the culture developed over the years and passed on through generations which includes the code of conduct, way of life, symbols, beliefs, norms, actions, etc (Cole 1996). Cultures have played an important role in documenting resources, materials and transcripts for different fields of life. Age related increase in need for culture is based on two premises, firstly for evolutionary system to take its course an individual needs to learn and build upon this learning for which the primary resource and base is culture (Valsiner & Lawrence 1997). Secondly, as an individual ages dependency on and need for culture based resources increases to support functioning (Dixon & Backman 1995). Age-Related Decline in Efficacy of Culture As individual ages reflexes and knowledge acquiring abilities become slower for which training, assistance and reminding is needed (Klix 1993). Efficiency in learning adopting and adapting to culture with age reduces. Older adults take longer to comprehend and learn things even with repeated trainings and information access (Baltes 1997). However, there are some objections to this ideology as it is believed that culture is inherently learned and embraced at earlier stages of life which cannot alter the lifespan development function at an older age. LIFESPAN CHANGES AND RESOURCES TO DIFFERENT ASPECTS OF DEVELOPMENT The extent to which aging, biological factors and culture pave the way in development of an individual keeping in mind the challenges faced in life. This aspect can be touched upon by looking at the three main aims of ontogenetic development; these three components are based on a person’s growth, individual maintenance as well as guidelines of loss. Growth means achieving higher levels of functioning of an individual while maintenance means sustaining the level of development and regulation of loss describes declining levels of maintenance due to challenges resulting in loss of maintenance of existing level of functioning. This distribution of resources in the lifespan alteration is essential to theory of lifespan growth. In addition it is also important to comprehend that these resources interplay between the aims of human development. It is interdependence that is the premise of life while the goal shifts to dependence in older age. The balance between individuality and dependence is critical. Older people by depending more become open to personal growth and efficacy, meaning even though dependence tends to increase and biological weakness prevails growth is still possible in older age (Greve, 1994). Deficits cause with age are complemented with the support of culture and compensated by the nature of human organism designed to deal with biological deficits allowing growth in the capacity of an individual (Gehlen 1956). Therefore, with the vulnerability of age factors excessive effort needs to be invested in facilitating growth. DEVELOPMENT AND ITS IMPACT ON ADAPTIVE CAPACITY From a LP point of view, it is important to emphasize concepts of development that are based on traditional concepts of biology and physical growth. These have to do with viewing the traditional elements of development, which focus on the aspects of qualitative change, irreversibility, and looking at the concept of end state. In theory developmentalists have been forming models around the traditional approaches of development and growth related to the functioning of human mind. In this process they have done modifications and added to the literature for example Labouvie- Vief (1982, 1992) introduced new stages of systemic functioning for the period of adulthood. Baltes (1998) introduced a model outlining the relationship between development with respect to age and related adaptive capacity of individuals for understanding and creating development systems. DEVELOPMENT BASED ON A GAIN-LOSS DYNAMIC Apart from the functionalist arguments pertaining growth and advancement in research and theory proved that development is always constituted by gains and losses. Researchers were able to highlighted gains and losses co-exist giving birth to intelligence (Horn & Hofer 1992). Furthermore, it was established that life development methodologies restricted to one aspect (functional approach) can not suffice the development process and its evaluation alone. Reason being complex human nature and changing circumstances of differing characteristics of individuals (Berg 1996). Hence the traditional view was empirically proven inappropriate. A more recent theory conceptualizes the term equifinality adding to the literature, meaning that with different combination of resources different individuals with varying capacities and through multifunctunality of resources same results can be acquired (Kruglanski 1996). Plasticity and Age-Associated Changes The concept of intaindividual plasticity pinpoints the search for the prospective of development encompassing its upper and lower boundary conditions. The concept depicts that diverse and many different development outcomes are possible and the range of ontogenetic plasticity as far as age varying factors are concerned is a key part of the study that looks at development. There are many approaches looked at by psychologists as far as the concept of plasticity is concerned however the ones that stand out most are those which look at the main differences between the baseline and developmental reserve capacity. While Baseline reserve capacity looks at the present level of plasticity that is available to a person. The developmental reserve capacity aims to analyze the specific possibilities in principle that are possible over developmental time, in the case that interventions are done. Furthermore research was done to understand the depth of the relationship between plasticity and age-oriented development (Kliegl et al 1989). Methodological Developments Metatheory and research methodology have been entwined since the inception of the lifespan development psychology and efforts to find other effective methods for study are still being searched by the lifespan researchers (Lindenberger & Potter 1998). ANALYSIS OF LIFE EVENTS AND HISTORY With the help of life-course sociologists researchers have been able to highlight the impact of hazards, events, survival rates, morality, death, etc on the process of development for which models of event history analysis are established (Blossfeld & Rohwer 1995). These aspects of life are crtical events in the lives of individuals for lifespan researches to study as with age surviving age keeps on declining proportionately having an impact on the nature of ontogenetic functioning (Lindenberger et al 1998). EVALUATING LIMITS OF PLASTICITY Over time researchers have advanced with methodological innovation for examining the scope and parameters of plasticity (Lindenberger & Baltes 1995). However, even with the advancements made it is still difficult to categorize the scope and parameters of plasticity and its age related changes. Furthermore, the contingencies of human development like cognitive aging and physical or biological aging increase the complexity of the methodology and research processes. Researchers have developed alternative models to overcome such problems example in testing the limits research age or time is compressed in order to provide high density developmental experience to identify plasticity (Kliegl et al 1989). This helps guess the potential of growth at on older age. Testing-the-limits technique and additional such models aid not only compensating for the age factor but also other varying factors such as the cognitive learning of different individuals. Though, to prove the effectiveness of testing the limits method individuals with different ages, cognitive functioning and individuals with similar functioning like twins should be experimented on. Most findings of behavior genetics are descriptive and based on ex post analysis (Lerner 1995). The Mechanics of Cognition In cognitive-intellectual operations it is supposed that the cognitive mechanics are indexed by the speediness, precision, and organization of elementary processing procedures. In these mechanics of cognition, biological (e.g. brain-related) conditions reign supreme, and the principal lifespan pattern shows maturation, stability, and aging-induced decline. In the early ages, that is first half of the lifespan learning and development have a faster pace and broader horizons with individuals having the capacity to process and develop more capabilities in a shorter span of time. In the other hand as age takes over there is pathological dysfunctioning and due to the aging of the brain the development process slows down (Morrison & Hof 1997). A LOOK AT THE LIFESPAN FACTORS OF THE COGNITIVE MECHANICS Researchers have been trying to identifying the pace at which and the determinants of rate of development related to age based changes and the cognitive changes and differences example In cognitive mechanics there have been three areas recognized as the controllers of development Information processing rate (Salthouse 1996), that is the speed with which child development takes place or can be executed; Working memory (Just et al 1996) the ability to hold on to information in the short run and over the passage of time with new information being parted and Inhibition. Psychometric tests of perceptual speed are used currently to evaluate the speed of information processing rate (Fry & Hale 1996), while the results are often unclear as it is unknown whether the information processing rate is depicting the sensory functioning or contributions from working memory. Working memory in itself is often difficult to judge as any changes that are caused by age are likely to alter the processing speed of the memory. Working memory is basically a structure of thoughts and behavior (Duncan et al 1996) therefore it becomes central to determining the intellectual development of an individual. Stroop color water test and other such tests are used to observe the changes in processing rate over the curvilinear lifespan age to measure the selective learning (Plude et al 1994) rather than age changes in inhibitory functioning. The lack of clarity in these search tools has led to considerations at the front of a number of approaches like the multivariate-psychometric; some other approaches that can be highlighted are the cognitive-experimental, and radically reductionist approaches (Hertzog 1996). To get a complete picture of the topic neurosciences needs to be involved for examining the differences amongst individuals as well as changes between each individual. Pragmatics of Cognition In the other hand the pragmatics of cognition bases its research and evaluation of development of the underlying factors and role of culture and knowledge based forms of intelligence as a part of growing up process (Marsiske & Willis 1998). The pragmatics of cognition highlight the cultural values learned and inculcated in individuals through their life experiences and socialization which can be classified into three categories of pragmatic knowledge normative but specific to certain cultures, universal and idiosyncratic or person specific. The pragmatic knowledge is enhanced with evolution and directs actions, intellect biographies and contexts of individuals which are in line with the biological architecture of an individual (Siegler & Crowley 1994). NORMATIVE AND SPECIFIC PRAGMATIC KNOWLEDGE Normative pragmatic knowledge is universal or general in value that is it is same across culture or sometimes even within culture example language proficiency meaning that people within a culture speak the same language while in most cases people with different cultural background also speak the same language however there might a difference in accent and a few geographically different words that maybe added to the language as is the case of spoken English across the globe, religion, etc. Individual differences within similar culture are due to difference in levels of education, exposure and experiences (Carroll 1993). Individual specific pragmatic knowledge is merely a collection of an individual’s personal learning process based on perception, motivational constellations, characteristics, talent, skills, etc (Marsiske et al 1995). However, these attributes of human mind and development are hard to study using the information from psychometric operationalization. So this aspect is viewed by making use of the expertise paradigm of conceptions that are key to the elements of cognitive functioning. Second conclusion drawn is the power of pragmatic knowledge to make up for losses in the mechanics within the domain of expertise meaning age induced losses acquired in the process of development, learning and knowledge are evident as life planning, every day context of life, problem solving and other such reflex become slower with age. This conclusion is central to understanding the impact aging and its negative effects on intellectual knowledge gains within the realm of lifespan theory of selective optimization (Baltes & Carstensen 1996). INTELLECTUAL GROWTH DURING ADULTHOOD: STAGE CONCEPTIONS VS. FUNCTIONALIST APPROACHES Lifespan intellectual development can be subjected to or a consequence of stage like logic which is a step by step process in development of a reasoning mind and learning or if the traditional functionalist approach towards intellectual development related to acquiring of knowledge and growth are more effective (Labouvie-Vief, 1995). Piaget’s theory of cognitive development directs the search for stage like development during adulthood which has helped identifying different stages of cognitive development, which connects the stages of personality development with logical considerations example developing a mindset to deal with and in a contradicting situation (McAdams & Aubin 1998). However, reliability of these measures is restrictive as gathering indicators of stage like cognitive change are difficult not only to obtain but also to evaluate. In addition Piaget himself argues that late adolescents and adults would exhibit formal-operational reasoning within their areas of expertise but not necessarily across all domains of knowledge (Piaget 1972). Adult intellectual growth is tied up to the reasons underlying the factors operating across domains rather than within them example attainment of pragmatic knowledge. Hence, from a functionalist view point the structuralist search is based upon the search for bodies of procedural and genuine (fact bearing) knowledge being inclined towards generalization and meaning. In a broader perspective on the subject matter the structuralist theory on intellectual development of adults or an older age (second half of the life) is presumed to respond to the lifespan tendency towards the breakup of knowledge and and specialization brought by less general bodies of knowledge (Stich 1990). Wisdom is considered as an ideal example while studying the perspective of growth in adults while considering the aspect of cognitive pragmatics. This aspect highlights wisdom with relevance to the post formal stage of thinking. While, the functionalist approach to lifespan tradition views wisdom as the finest expression of learning and knowledge in the prime of fundamental pragmatics of life, meaning proficient and integrative knowledge about the significance and behavior of individuals in the conduct of life with the coordination of mind, thinking, emotions and personality (Sternberg 1990). Certainly the perceived deficiency or nonexistence of negative differences in adulthood related to performance with respect to wisdom up till the age of about 75 years and the premise that experiences throughout the span of life like that of professional specialization (Smith et al 1994) control the pace, direction and level of gradients of age in the cognitive mechanics. Furthermore, of the supreme presentations or acts of wisdom chores and tasks majority comes from the people at the later stages of adult age. Merely in extremely old age the mechanics are observed to restrict the wisdom related performance perhaps due to the fall below the precarious threshold of functional integrity (Baltes et al 1995). Initially, research and exploration of/on wisdom was driven and inspired by the interest for finding the positive characteristics and traits of aging of individuals. The scope of this search process has stretched to encompass the clinical psychology, cultural psychology and the cognitive psychology of heuristics (Staudinger 1996). As the search process continues some researches argue that wisdom is a motivational and cognitive approach that composes of various and assorted bodies of knowledge regarding human excellence (Baltes 1998). A refined experiment pertains to the conduct of life with respect to wisdom which guards the fragmentation of knowledge and boosts the control of an individual’s vices and the optimization of and individual’s virtues. Given this argument wisdom can be defined as a lifetime general purpose heuristic directed towards keeping well of an individual and the wellbeing of people around (Stich 1990). Plasticity (Malleability) in Intellectual Functioning: Evidence from Adult Development As per research it has been determined that lifespan changes in intellectual functioning are subjected by a number of varying sources of influence. As a result of which the varying levels of intellectual performance are swayed within the age depicting stages highlight by the mechanics, by deviations and distinctions in the society directed cultural values or physical features of environmental conditions which are connected with the differences and dissimilarities in the lifetime experiences, that being cognitive experiences. The methodological analysis of changes incurring on the intellectual development with respect to the environment at varying levels temporal extension and generality have aided in pinpointing the plasticity (malleability) of intellectual functioning, taking into account the changes associated or caused by age factor (Willis et al 1997). LOOKING AT COHORT AND PERIOD EFFECTS, AND ENVIRONMENTAL CHANGES Stages and forms of age levels or gradients in intellectual development of skills and capabilities are formed at varying graduations with the use of history graded systems of influence, for example differences between people who are born in different points on a timeline that is, different historical eras, the chronological arrangement of events in history shape the varying environments in which different individuals are born causing the difference on the general environment around them. Discriminating between these diversities of environmental changes over the timeline is a tedious task. The foremost footstep to determine effects of environmental changes on a broader level is to equate or match the performance of individuals of same age over the historical time, to be able to identify the time-lag contrasts. The framework or findings established from such comparisons are results of test scores which have been attained in the modern times (Schaie, 1996). The pattern observed over time, that is the increase in test results depicts improvements in health, education and work related conditions as the world systems have advanced and modernized. Such culturally based cohort effects were influential in pointing to the considerable malleability of intellectual performance during all periods of the adult life span. Research of cohort-sequential schemes put forward three distinct forms of comparisons through age. These three forms were cross-sectional, longitudinal and independent-samples. The Seattle Longitudinal Study the independent-sample same-cohort and cross-sectional comparisons generated decidedly and extremely alike approximations of a seven year change after the specialists or analysts controlled for the general increase in performance over the historical timeline (period) showed by the time-lag comparisons (Schaie,1996). On the contrary longitudinal age changes, when amended or adjusted for the historical change revealed a comparatively reduced decrement with age; Specified conjunction between cross sectional and independent sample same cohort comparisons, the more positive age levels or gradients observed with longitudinal samples could be in part the resultants of practice affects and selective attrition. COGNITIVE INTERVENTION WORK: LEARNING ABILITIES AMONG OLDER ADULTS Experimentally measured and controlled intrusions discover the degree of plasticity in intellectual functioning with in a more straightforward manner as compared to the cohort comparative research (Willis & Schaie 1994). The indication of the influential role of practice and experience in the attainment, modification, alteration and maintenance of the cognitive pragmatics is overpowering In this framework the investigation emphasizes on cognitive intervention work with the older aged individuals most relevant to the study of psychometric intelligence and connected tasks which seem to be nearer to the cognitive mechanics for example the tests of fluid intelligence. The prominent findings can be summarized into seven points; The carried out tests show that the ability to train healthy older adults of a certain age have the ability to show advanced developments Transfer, however, is limited to similar tests of the same ability Advances that resulted were seen as a aim of the self-guided experiments Practiced advances are maintained over lengthy periods of time up to several years the factor structure of the ability space is not changed alot through training (Schaie et al 1987) the amount of training gain is substantially reduced as people reach progressive old age and in persons at risk for Alzheimer’s disease or afflicted by other forms of brain pathology, learning gains are substantially reduced or nonexistent (Baltes et al 1995). At bounds of functioning and in the second half of the life that is older age, adults unquestionably exhibit a limited potential for learning and development from training (Lindenberger & Baltes 1997). The findings show that cognitive plasticity is the mechanics of cognition is well maintained and well-kept amid among older adults (old aged individuals) who are healthy and is easily triggered by experiential handlings (Woodruff-Pak 1993). Nonetheless the general absence of transfer of training to related abilities or to routine functioning submits the proposition that improvements in performance test of fluid intelligence mainly depict variations or changes in pragmatic mechanisms of performance potential, instead of the improvements in the cognitive mechanisms. CONCLUSION In recent times it has been observed that rigorous, wide ranging and diverse efforts are made to understand and evaluate the development of humans (individuals) from lifespan view point. The key objective of this study was to examine the levels of convergence amongst varying and diverse levels of empirical and theoretical analysis (Thelen & Smith 1998). It can be concluded that the efforts made on the study of lifespan development organized at varying levels of analysis demonstrates convergence and shows theoretical development, advancement and growth in lifespan development psychology. In developing and filtering the multi-level framework, lifespan developmental psychology has profited in various ways with the help of multiple disciplines understandings like that of neurosciences and modern biologists, cultural psychologists, etc. Biologists, for one, have paved the doorway towards directing research away from unilinear, unifunctional and deterministic models of ontogenesis to a theoretical context that points out several characteristics of development. These comprise of adaptive, self-guiding, and contextual aspects. Similarly, cultural psychologists and development / ontogenesis oriented social scientists have thrived equally in establishing and signifying that human development is immensely influenced by culture and the architecture of human development is more importantly fundamentally incomplete or lacking due to biological incompleteness as well as due to the culturally caused trails and possible endpoints (Elder 1999). The future of lifespan development theory and study is dependent considerably on the degree to which the metatheoretical and pragmatic standpoints or perspectives that have emerged materialize to be valuable and beneficial in the conduct of development study and furthermore, in representing the helpfulness and advantageousness of the lifespan theory’s approach for a greater number of psychological fields of specialization with respect to and with an emphasis on culture. References Baltes M, Carstensen L. 1996. The process of successful ageing. Aging Sociology. 15: 395–422 Baltes, Carstensen L. 1998. Social psychological theories and their applications to aging: From individual to collective social psychology. New York: Springer. In press Baltes M, Kuhl P, Gutzmann H, Sowarka D. 1995. Potential of cognitive plasticity as a diagnostic instrument: a crossvalidation and extension. Psych. Aging 11:166–72 Baltes M, Lang R. 1997. Differences in everyday functioning between successfully and unsuccessfully aging adults. Psych. Aging 11:434–43 Baltes B. 1983. Life-span developmental psychology: observations on history and theory revisited. pp. 79–111. Hillsdale, NJ: Erlbaum Baltes B. 1993. The aging mind: potential and limits. Gerontologist 33:579–94 Baltes B. 1997. Architecture of human ontogeny: selection, optimization, and compensation as foundation of developmental theory. Psychol. 51:366–80 Baltes B, Baltes M. 1990. Psychological perspectives on successful aging: the model of selective optimization with compensation. Perspectives from the Behavioral Sciences Baltes B, Brim Jr. 1979. Life-Span Development and Behavior, vol. 2, New York: Academic Baltes B, Goulet R. 1970. Status and issues of a life-span developmental psychology. In Life-Span Developmental Psychology: Research and Theory, pp. 4–21. New York: Academic Baltes B, Kliegl R. 1992. Further testing of limits of cognitive plasticity: negative age differences in a mnemonic skill are robust. Dev. Psych. 28:120–25 Baltes B, Lindenberger U. 1997. Emergence of a powerful connection between sensory and cognitive functions across the adult life span. Psych. Aging 12:11–21 Baltes B, Lindenberger U, Staudinger UM.1998. Life-span theory in developmental psychology. See Lerner 1998b, pp. 102–143 Baltes B, Reese W and Lipsitt. 1980. Lifespan developmental psychology. Psych. 31:65–110 Baltes B, Reese W and Nesselroade. 1988. Life-Span Developmental Psychology: Introduction to Research Methods. Hillsdale, NJ: Erlbaum Baltes B, Smith J. 1997. A systemic- wholistic view of psychological functioning in very old age: introduction to a collection of articles from the Berlin Aging Study. Psych. Aging 11:394–409 Baltes B and Staudinger. 1993. The search for a psychology of wisdom. Psychol. Sci. 2:75–80 Baltes P and Staudinger. 1996. Interactive Minds: Life-Span Perspectives on the Social Foundation of Cognition. NewYork: Cambridge U Press Baltes, Staudinger, Maercker and Smith J. 1995. People nominated as wise: a comparative study of wisdom-related knowledge. Psych Aging 10:150–66 Berg C. 1996. Practical intelligence and problem solving: searching for perspectives. pp. 320–57 Blossfeld, Rohwer G. 1995. Techniques of Event History Modeling. New Approaches to Causal Analysis. Mahwah, Erlbaum Birren E, Schaie W,1996. Handbook of the Psychology of Aging. San Diego: CA: Academic. 4th ed Brandtstadter J. 1998. Action perspectives on human development. pp. 806–66 Brandtstadter J, Greve W. 1994. The aging self: stabilizing and protective processes. Dev. Rev. 14:50–80 Carroll. 1993. Human Cognitive Abilities. Cambridge Univ. Press Case R. 1985. Intellectual Development: From Birth to Adulthood. New York: Academic Cole M. 1996. Interacting minds in a lifespan perspective: a cultural/historical approach to culture and cognitive development, pp. 58–87 Dixon R and Backman L. 1995. Compensating for Psychological Deficits and Declines: Managing Losses and Promoting Gains. Mahwah, NJ: Erlbaum Dixon R, and Gould N. 1996. Adults telling and retelling stories collaboratively. pp. 221–41 Finch E. 1996. Biological bases for plasticity during aging of individual life histories. In The Life-Span Development of Individuals, pp. 488–511. Cambridge Univ. Press Grober E and Kawas C. 1997. Learning and retention in preclinical and early Alzheimers disease. Psych. Aging 12:183- 89 Horn L. 1989. Models of intelligence. In Intelligence: Measurement, Theory, and Public Policy, pp. 29 -73. Univ. Ill. Press Kliegl R, Mayr U and Krampe T. 1994. Time- accuracy functions for determining process and person differences: an application to cognitive aging. Cogn. Psych. 26:134–66 Kliegl R, Smith J and Baltes B. 1989. Testing-the-limits and the study of age differences in cognitive plasticity of a mnemonic skill. Dev. Psych. 25:247–59 Labouvie-G. 1982. Dynamic development and mature autonomy: a theoretical prologue. Hum. Dev. 25:161-90 Labouvie-G. 1992. Neo-Piagetian perspective on adult cognitive development. pp. 197-228 Labouvie-G. 1995. Mind and Gender in the Life Course. New York: Cambridge Univ. Press McAdams P, de St. Aubin E. 1998. Generativity and Adult Development. Washington, DC: Am. Psych. Assoc Schaie W. 1994. The course of adult intellectual development. Am. Psych. 49:304-14 Schaie W. 1996. Adult Intellectual Development: The Seattle Longitudinal Study. New York: Cambridge Univ. Press Schaie W, Willis F, Hertzog C and Schulenberg E. 1987. Effects of cognitive training on primary mental ability structure. Psych. Aging 2:233- 239 Willis L, Schaie W and Hayward M. 1997.Societal Mechanisms for Maintaining Competence in Old Age. New York: Springer Read More