01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 3 1 CHAPTER Historical and Theoretical Bases of Applied Developmental Science R M. L ICHARD ERNER D W ONALD ERTLIEB F J RANCINE ACOBS The latter part of the 20th century problems (Dryfoos, 1990; Hamburg, 1992; was marked by public anxiety about Hernandez, 1993; Huston, 1991; Lerner, myriad social problems, some old, 1995; Lerner & Fisher, 1994; Schorr, 1988, some new, but all affecting the lives of 1997). And if people were not dying, their vulnerable children, adolescents, adults, prospects for future success were being families, and communities (Fisher & Murray, reduced by civil unrest and ethnic conflict, 1996; Lerner, 1995; Lerner & Galambos, by famine, by environmental challenges 1998; Lerner, Sparks, & McCubbin, 1999). (e.g., involving water quality and solid- For instance, in America, a set of problems of waste management), by school under- historically unprecedented scope and severity achievement and dropping out, by teenage involved interrelated issues of economic pregnancy and parenting, by lack of job development, environmental quality, health opportunities and preparedness, by pro- and health care delivery, poverty, crime, vio- longed welfare dependency, by challenges to lence, drug and alcohol abuse, unsafe sex, their health (e.g., lack of immunization, and school failure. inadequate screening for disabilities, insuffi- Indeed, in the last years of the 20th cient prenatal care, and lack of sufficient century and the first years of the present infant and childhood medical services), and one, across the United States and in other by the sequelae of persistent and pervasive nations, infants, children, adolescents, and poverty (Dryfoos, 1990; Huston, 1991; the adults who care for them continued Huston, McLoyd, & Garcia Coll, 1994; to die from the effects of these social Lerner, 1995; Lerner et al., 1999; Lerner & 3 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 4 4 FOUNDATIONS OF APPLIED DEVELOPMENTAL SCIENCE Fisher, 1994). These issues challenge the field as a sample case, we may note that resources and the future viability of civil several extensive histories of developmental society in America and throughout the psychology have been published and most world (Lerner, Fisher, & Weinberg, 2000a, include references to the ebb and flow of 2000b). interest and priority for what might be The potential role of scientific knowledge termed the applied, practical, or societally about human development in addressing oriented issues central to ADS. Especially these issues of individuals, families, com- relevant are discussions offered by Bronfen- munities, and civil society has resulted in brenner, Kessel, Kessen, and White (1986); growing interest and activity in what has Cairns (1998); Davidson and Benjamin been termed applied developmental science (1987); Hetherington (1998); McCall (ADS). Indeed, over the last two decades, (1996); McCall and Groark (2000); Sears increasing numbers of developmental scien- (1975); Siegel and White (1982); Parke, tists from diverse disciplines have come to Ornstein, Reiser, and Zahn-Waxler (1994), identify themselves professionally as applied Zigler (1998); and Zigler and Finn-Stevenson developmental scientists. Joining under this (1992, 1999). Hetherington (1998) frames umbrella are colleagues from allied disci- her analysis by accenting her use of the term plines and specialties in the biological, psy- “developmental science...to emphasize chological, social, and behavioral sciences both the scientific and multidisciplinary and the helping professions, all sharing foundations of the study of development common goals and visions captured in some and the recognition that development is not of the more formal definitions of the ADS confined to childhood but extends across the field. life span” (p. 93), an emphasis that is lost or In many ways, ADS is “old wine in a diluted in the too-limiting term child psy- new bottle”; that is, significant historical chology. Hetherington interprets and extends antecedents to the burgeoning field are evi- Sears’s (1975) classic analysis, reaffirming dent today (Wertlieb, 2003). It is useful here that “unlike many areas in psychology [with to provide a brief overview of this history, their histories documented by Boring focusing most on the events over the last (1950) and Koch & Leary (1985)], develop- quarter of a century that have given shape to mental science originated from the need to contemporary ADS. solve practical problems and evolved from pressure to improve the education, health, welfare and legal status of children and their families” (p. 93). APPLIED DEVELOPMENTAL The chronology of developmental psy- SCIENCE: A BRIEF HISTORY chology offered by Cairns (1998) serves as a useful framework within which to specify ADS has its roots in numerous fields some of the distinctive or seminal elements concerned with human development, for of ADS. Cairns segments the emergence of example, home economics/family and con- developmental psychology (1882-1912), the sumer sciences (Meszaros, 2003; Nickols, middle period of institutionalization and 2002), human ecology (Bronfenbrenner & expansion (1913-1946), and the modern Morris, 1998), comparative psychology era (1947-1976). His compliance with a (Tobach, 1994), and developmental psy- convention that 20 years must elapse before chology (Wertlieb, 2003). Using the latter qualifying as “historical” leaves much of 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 5 Historical and Theoretical Bases 5 the significant milestone material in the own perspective. For instance, Bronfenbrenner defining of ADS, to be mentioned below, et al. (1986) noted, outside the realm of his presentation, although he does conclude his account with The simple fact is that G. Stanley Hall marched away from experimental psycho- a clarion anticipation of and call for more logy toward the study of children because integrated interdisciplinary science, quite at least six different constituencies existed consistent with what we might term the in American society, basically still our postmodern or contemporary era (1977 to constituencies today—scientists, college administrators, child savers and social the present). Indeed, it will be from this workers, mental health workers, teachers, most recent period that we draw our sub- and parents. These constituencies wanted stantive examples of ADS, after the conclu- certain kinds of knowledge about children. sion of this historical sketch. Mirabile dictu, without even being devel- opmental psychologists and before we Most accounts, including Cairn’s came into existence, they were all collect- (1998) “emergence” analysis, portray the ing data that look like ours. So, if you look dialectic at the base of ADS as pioneered at the social history that surrounds the by G. Stanley Hall, the first professor of birth of the Child Study Movement, you psychology in America (appointed in 1883 gradually come to the conclusion that per- haps we represent a professionalization of at Johns Hopkins University), the first trends of knowledge gathering and knowl- president of the American Psychological edge analysis that existed in our society Association (1891), and founder of the first before our coming. That doesn’t com- child development research institute at pletely detach us from the mainstream of the history of psychology, but it certainly Clark University and of the journal, throws a very different light on the emer- Pedagogical Seminary. gence and evolution of the field and its basic issues. (p. 1221) Hall was a remarkable teacher and catalyst for the field. Some of the most significant Among Hall’s most significant contribu- areas for developmental study—mental test- tions, according to White (1992), were the ing, child study, early education, adoles- cence, life span psychology, evolutionary concern with descriptions of children in their influence on development—were stimulated natural contexts and the priority need “to or anticipated by Hall. Because of short- arrive at a scientific synthesis on the one comings in the methods he employed and side and practical recommendations on the theory he endorsed, few investigators the other” (as cited in Cairns, 1998, p. 43). stepped forward to claim Hall as a scientific mentor. His reach exceeded his grasp in the Contemporary ADS continues in its value plan to apply the principles of the new sci- in the former and aspires to overcome the ence to society. Psychology’s principles were too-dichotomous implications of the second; too modest, and society’s problems too it emphasizes the reciprocal and mutual large. Perhaps we should use a fresh accounting to judge Hall’s contributions, interactions of the scientific and practical one that takes into account the multiple that were typical in this earliest era. facets of his influence on individuals, the Within the last quarter of a century, a discipline, and society. The audit would key milestone in the elaboration of the reveal that all of us who aspire to better the lot of children and adolescents can claim field’s territory occurred with the founding him as a mentor. (Cairns, 1998, p. 43) of the Journal of Applied Developmental Psychology, in 1980, an international multi- White (1992) points to the work of disciplinary life span journal. The masthead Bronfenbrenner as being consistent with his proclaimed: 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 6 6 FOUNDATIONS OF APPLIED DEVELOPMENTAL SCIENCE A forum for communication between organizations concerned with the application researchers and practitioners working in of the developmental psychology knowledge life span human development fields, a forum base to societal problems. Organizations rep- for the presentation of the conceptual, methodological, policy, and related issues resented included the American Psychological involved in the application of behavioral Association (APA), the Gerontological Society science research in developmental psychol- of America, the International Society for ogy to social action and social problem Infant Studies, the National Black Child solving. (Sigel & Cocking, 1980, p. i) Development Institute, the National Council In welcoming the new journal in an on Family Relations, the Society for Research inaugural editorial, Zigler (1980) narrowed on Adolescence, and the Society for Research the definition of the journal’s purview to in Child Development. Goals included the what he called a “field within a field” (i.e., articulation of the definition and scope of presumably, applied developmental psy- ADS along with guidelines for graduate train- chology within developmental psychology) ing in this emergent interdisciplinary field. A but set high and broad expectations that consensus process produced a complex four- “these pages shall attest to the synergistic point definition of ADS, quoted here at relationship between basic and applied length to document the current parameters research” (p. 1). of content, process, methods, and values: Almost 20 years later, Zigler (1998) issued a similar note of hope, celebration, 1.1. Applied developmental science involves and welcome in a significant essay called the programmatic synthesis of research “A Place of Value for Applied and Policy and applications to describe, explain, Studies,” this time in the pages of Child intervene, and provide preventive and enhancing uses of knowledge about Development, the prestigious archival jour- human development. The conceptual nal of the Society for Research in Child bases of ADS reflects the view that indi- Development (SRCD). Child Development vidual and family functioning is a com- had been singularly devoted to... bined and interactive product of biology and the physical and social environ- Theory-driven, basic research. Now, after ments that continuously evolve and more than six decades of advancing science change over time. ADS emphasizes the as a means to expand our understanding of nature of reciprocal person-environment human development, SRCD has formally interactions among people, across welcomed into its major journal research settings, and within a multidiscipli- that uses this knowledge on children’s nary approach stressing individual and behalf...the result of a very gradual trans- formation within SRCD from a scientist’s cultural diversity. This orientation is science toward a more public science. defined by three conjoint emphases: (Zigler, 1998, p. 532) Applied: Direct implications for what individuals, families, practitioners, and The continuing vicissitudes of the gaps and policymakers do. synergies between applied and basic research will be a theme of the historical sketch offered Developmental: Systematic and succes- below (see also Garner, 1972). sive changes within human systems that occur across the life span. In 1991, the National Task Force on Applied Developmental Science convened Science:Grounded in a range of research representatives from a broad, but not methods designed to collect reliable and exhaustive, range of professional scientific objective information systematically that 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 7 Historical and Theoretical Bases 7 can be used to test the validity of theory developmental science across the life span. and application. Manuscripts pertinent to the diversity of development throughout the life span— 1.2. ADS recognizes that valid applications cross-national and cross-cultural studies; of our knowledge of human develop- systematic studies of psychopathology; and ment depend on scientifically based studies pertinent to gender, ethnic and understanding of multilevel normative racial diversity—are particularly welcome. ...(The audience includes) developmental, and atypical processes that continually clinical, school, counseling, aging, educa- change and emerge over the life cycle. tional, and community psychologists; life course, family and demographic socio- 1.3. ADS reflects an integration of perspec- logists; health professionals; family and tives from relevant biological, social, consumer scientists; human evolution and and behavioral sciences disciplines in ecological biologists; practitioners in child the service of promoting development in and youth governmental and nongovern- various populations. mental organizations. (p. 1) 1.4. The nature of work in ADS is reci- procal in that science drives application This amplified definition of ADS pos- and application drives science. ADS tulates a number of hallmarks of ADS key emphasizes the bidirectional relationship to the discussion of its history, content, and between those who generate empirically special concerns. Among these hallmarks are based knowledge about developmental phenomena and those who pursue pro- the following: fessional practices, services, and policies that affect the well-being of members of society. Accordingly, research and 1. A historical context and perspective theory guide intervention strategies, reflecting the perennial balancing of related and evaluations of outcomes of develop- constructs such as basic and applied research mental interventions provide the basis or science and practice or knowledge gene- for the reformulation of theory and for ration and use. This includes a sensitivity modification of future interventions. to historical and sociopolitical contexts (Fisher et al., 1993, pp. 4-5) captured in the notion of ADS as... Scholarship for our times....As we enter By 1997, these parameters defining ADS the 21st century, there is growing recogni- were adopted as the editorial scope of a new tion that traditional and artificial distinc- journal, Applied Developmental Science, tions between science and service and with further explication of a more inclusive between knowledge generation and knowl- edge application need to be reconceptual- range of methodologies and audiences. ized if society is to successfully address the According to Lerner, Fisher, and Weinberg harrowing developmental sequelae of the (1997), the journal publishes ... social, economic and geo-political legacies of the 20th century. Scholars, practitioners and policymakers are increasingly recogniz- Research employing any of a diverse array ing the role that developmental science can of methodologies—multivariate longitudi- play in stemming the tide of life chance nal studies, demographic analyses, evalua- destruction caused by poverty, premature tion research, intensive measurement births, school failure, child abuse, crime, studies, ethnographic analyses, laboratory adolescent pregnancy, substance abuse, experiments, analyses of policy and/or unemployment, welfare dependency, dis- policy-engagement studies, or animal com- crimination, ethnic conflict, and inadequate parative studies—when they have impor- health and social resources. (Lerner et al., tant implications for the application of 1997, p. 2) 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 8 8 FOUNDATIONS OF APPLIED DEVELOPMENTAL SCIENCE 2. A broadened and deepened awareness FROM DEVELOPMENTAL SYSTEMS of the ethical challenges and imperatives THEORIES TO APPLIED involved in implementing the scope of ADS. DEVELOPMENTAL SCIENCE This awareness evolves from challenges in the use of scientific methods in new ways Paul Mussen, the editor of the third edition such that protection of the autonomy and of the Handbook of Child Psychology, pre- well-being of participants is increasingly saged what today is abundantly clear about complex. Research participants become the contemporary stress on systems theories partners in the inquiry process and new, of human development. Mussen (1970) said, more complicated collaborations among “The major contemporary empirical and diverse multidisciplinary professionals and theoretical emphases in the field of devel- communities become key elements of defin- opmental psychology...seem to be on ing research questions and problems and explanations of the psychological changes seeking answers and solutions. that occur, the mechanisms and processes accounting for growth and development” Moreover, as implied earlier in the chap- (p. vii). This vision alerted developmental ter, some leaders of ADS have seen the need scientists to a burgeoning interest—not in to further broaden the potential scope of this structure, function, or content per se, but in field, suggesting elements of a blueprint for change, in the processes through which promoting civil society and social justice, a change occurs, and in the means through provocative and compelling elaboration of which structures transform and functions both the substance and ethical orientation of evolve over the course of human life. the field (Lerner et al., 2000b). Others have Today, Mussen’s (1970) vision has been focused on more traditional, academic, or crystallized. The cutting edge of contemporary incremental stocktaking for defining ADS, developmental theory is represented by with attention to advancing the numerous systems conceptions of the process of how knowledge bases and methodologies (e.g., structures function and how functions are Schwebel, Plumert, & Pick, 2000; Shonkoff, structured over time. Thus, developmental 2000; Sigel & Renninger, 1998). However, systems theories of human development are given the presence of this range of interests not necessarily tied to a particular content and activities, ADS is now considered “an domain, although particular empirical issues established discipline” (Fisher, Murray, & or substantive foci (e.g., motor development, Sigel, 1996), one that is operationalized by successful aging, wisdom, extraordinary cog- the diverse foci of work pursued under nitive achievements, language acquisition, the this framework but is linked by a common self, psychological complexity, or concept for- conceptual/theoretical perspective about mation) may lend themselves readily as exem- human development: developmental systems plary sample cases of the processes depicted in theory. To understand the diversity of a given theory (see Lerner, 1998a). empirical, methodological, and ethical inter- The power of developmental systems the- ests and activities of contemporary ADS, it is ories lies in their ability to not be limited or important to appreciate the developmental confounded by an inextricable association systems theoretical orientation that rational- with a unidimensional portrayal of the devel- izes the use of developmental science for the oping person. In developmental systems promotion of positive human development theories, the person is neither biologized, and the enhancement of civil society. psychologized, nor sociologized. Rather, 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 9 Historical and Theoretical Bases 9 the individual is systemized. A person’s words, development,understood as a property development is embedded within an inte- of systemic change in the multiple and inte- grated matrix of variables derived from mul- grated levels of organization comprising tiple levels of organization. Development is human life and its ecology (ranging from biol- conceptualized as deriving from the dynamic ogy to culture and history), is an overarching relations among the variables within this conceptual frame associated with developmen- multitiered matrix. tal systems models of human development. Developmental systems theories use the polarities that engaged developmental theory Explanation and in the past (e.g., nature/nurture, individual/ Application: A Synthesis society, biology/culture; Lerner, 1976, 1986, 2002b). They are not used to “split” depic- This stress on the dynamic relation tions of developmental processes along between the individual and his or her con- conceptually implausible and empirically text results in the recognition that a synthe- counterfactual lines (Gollin, 1981; Overton, sis of perspectives from multiple disciplines 1998) or to force counterproductive choices is needed to understand the multilevel inte- between false opposites (e.g., heredity or grations involved in human development. In environment, continuity or discontinuity, addition, to understand the basic process of constancy or change; Lerner, 2002b), but human development, both descriptive and rather to gain insight into the integrations explanatory research must be conducted that exist among the multiple levels of orga- within the actual ecology of people’s lives. nization involved in human development. Explanatory studies, by their very nature, These theories are certainly more complex constitute intervention research. The role of than their one-sided predecessors. They are the developmental researcher conducting also more nuanced, more flexible, more bal- explanatory research is to understand the anced, and less susceptible to extravagant ways in which variations in person-context or even absurd claims: for instance, that relations account for the character of human nature split from nurture can shape the developmental trajectories, life paths that are course of human development; that there is a enacted in the natural laboratory of the real gene for altruism, militarism, or intelligence; world. To gain an understanding of how or that when the social context is demon- theoretically relevant variations in person- strated to affect development, the influence context relations may influence developmen- can be reduced to a genetic one (e.g., tal trajectories, the researcher may introduce Hamburger, 1957; Lorenz, 1966; Plomin, policies and/or programs as experimental 1986, 2000; Plomin, Corley, DeFries, & manipulations of the proximal and/or distal Faulker, 1990; Rowe, 1994; Rushton, 1987, natural ecology. Evaluations of the outcomes 1988a, 1988b, 1997, 1999). of such interventions become a means to These mechanistic and atomistic views bring data to bear on theoretical issues perti- of the past have been replaced, then, by theo- nent to person-context relations. More retical models that stress the dynamic synthesis specifically, these interventions have helped of multiple levels of analysis, a perspective applied developmental scientists understand having its roots in systems theories of biologi- the plasticity in human development that cal development (Cairns, 1998; Gottlieb, may exist and that may be capitalized on to 1992; Kuo, 1930, 1967, 1976; Schneirla, enhance human life (Csikszentmihalyi & 1956, 1957; von Bertalanffy, 1933). In other Rathunde, 1998; Lerner, 1984). 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 10 10 FOUNDATIONS OF APPLIED DEVELOPMENTAL SCIENCE The interindividual differences in intrain- then, basic research in human development is dividual change that exist as a consequence intervention research (Lerner et al., 1994). of these naturally occurring interventions Accordingly, the cutting edge of theory attest to the magnitude of the systematic and research in human development lies changes in structure and function—the in the application of the conceptual and plasticity—that characterizes human life. methodological expertise of human develop- Explanatory research is necessary, however, mental scientists to the natural ontogenetic to understand which variables, from which laboratory of the real world. This placement levels of organization are involved in partic- of explanatory research about the basic ular instances of plasticity that have been relational process of development into the seen to exist. In addition, such research is actual ecology of human development, then, necessary to determine which instances of involves the fusion of application with basic plasticity may be created by science or soci- developmental science. To pursue the study ety. In other words, explanatory research is of ontogeny from a developmental systems needed to ascertain the extent of human plas- perspective, a research/application agenda ticity or in turn, to test the limits of plasticity that focuses on the relations between diverse (Baltes, 1987; Baltes, Lindenberger, & individuals and their similarly diverse con- Staudinger, 1998; Lerner, 1984). texts is brought to the forefront (Lerner, From a developmental systems perspec- 2002b). In addition, however, scholars tive, the conduct of such research may lead involved in such research must have at least the scientist to alter the natural ecology of two other concerns deriving from the view the person or group he or she is studying. that basic explanatory research in human Such research may involve either proximal development is, in its essence, intervention and/or distal variations in the context of research. human development (Lerner & Ryff, Research in human development that is 1978); but in any case, these manipulations concerned with one or even a few instances constitute theoretically guided alterations of individual and contextual diversity can- of the roles and events a person or group not be assumed to be useful for understand- experiences at, or over, a portion of the life ing the life courses of all people. Similarly, span. policies and programs derived from such These alterations are indeed, then, inter- research or associated with it in the context ventions: They are planned attempts to alter of a researcher’s tests of ideas pertinent to the system of person-context relations that human plasticity cannot hope to be applica- constitute the basic process of change; they ble or equally appropriate and useful in all are conducted to ascertain the specific bases contexts or for all individuals. Accordingly, of or to test the limits of particular instances policy development and program (interven- of human plasticity (Baltes, 1987; Baltes tion) design and delivery that are develop- & Baltes, 1980; Baltes et al., 1998). These mental and oriented to individual differences interventions are a researcher’s attempt to must be a key part of the approach to applied substitute designed person-context rela- developmental research for which we are tions for naturally occurring ones in an calling. attempt to understand the process of chang- The variation in settings within which ing person-context relations that provides people live means that studying development the basis of human development. In short, in a standard (for example, a controlled) 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 11 Historical and Theoretical Bases 11 environment does not provide information human development. To do this, we may pertinent to the actual (ecologically valid) make great use of the integrative, temporal, developing relations between individually and relational model of the person and distinct people and their specific contexts of his or her context that is embodied in (for example, their particular families, developmental system theories of human schools, or communities). This point development. underscores the need to conduct research in real-world settings (Bronfenbrenner, 1974; From Developmental Systems Theory Zigler, 1998) and highlights the ideas that to the Core Principles of ADS (a) policies and programs constitute natural experiments, that is, planned interventions As has been argued before us—for for people and institutions, and (b) the eval- example, by Fisher (e.g., Fisher et al., 1993; uation of such activities becomes a central Fisher & Lerner, 1994); Weinberg (e.g., focus in the developmental systems research Lerner et al., 1997, 2000a, 2000b); Sherrod agenda we have described (Cairns, Bergman, (e.g., 1999a, 1999b); Eccles (Eccles, Lord, & & Kagan, 1998; Lerner, 1995; Lerner, Buchanan, 1996); Takanishi (1993); Lerner Ostrom, & Freel, 1995; Ostrom, Lerner, & (Lerner, 1998b, 2002a, 2002b); and Freel, 1995). Wertlieb (2003)—ADS is scholarship predi- In this view, then, policy and program cated on a developmental systems theoreti- endeavors do not constitute secondary work cal perspective. Within this context, Fisher or derivative applications conducted after etal. (1993) summarize the five conceptual research evidence has been complied. Quite components that together characterize the to the contrary, policy development and core principles of ADS. Taken together, implementation and program design and these conceptual principles make ADS a delivery become integral components of the unique approach to understanding and ADS approach to research; the evaluation promoting positive development. component of such policy and intervention The first conceptual component of ADS work provides critical feedback about the is the notion of the temporality, or historical adequacy of the conceptual frame from embeddedness, of change pertinent to which this research agenda should derive individuals, families, institutions, and com- (Zigler, 1998; Zigler & Finn-Stevenson, munities. Some components of the context or 1992). of individuals remain stable over time, and In essence, then, a developmental systems other components may change historically. perspective leads us to recognize that if Because phenomena of human behavior and we are to have an adequate and sufficient development vary historically, one must science of human development, we must assess whether generalizations across time integratively study individual and contextual periods are legitimate. Thus, temporality has levels of organization in a relational and important implications for research design, temporal manner (Bronfenbrenner, 1974; service provision, and program evaluation. Zigler, 1998). We may also seek to serve Interventions are aimed at altering the America’s citizens and families through our developmental trajectory of within-person science and help develop successful policies changes. To accomplish this aim, the second and programs through our scholarly efforts conceptual feature of ADS is that applied that result in the promotion of positive developmental scientists take into account 01-Lerner (ADS).qxd 12/14/2004 8:24 PM Page 12 12 FOUNDATIONS OF APPLIED DEVELOPMENTAL SCIENCE interindividual differences (diversity) among, recognize the importance of knowledge for instance, racial, ethnic, social class, and about life and development that exists gender groups, and intraindividual changes, among the individuals, families, and commu- such as those associated with puberty. nities being served by ADS. For applied The third conceptual feature of ADS developmental scien-tists, collaboration and places an emphasis on the centrality of con- colearning between researchers/universities text. There is a focus on the relations among and communities are essential features of all levels of organization within the ecology the scholarly enterprise (Lerner, 1998a, of human development. These levels involve 1998b). Such community-collaborative biology, families, peer groups, schools, busi- efforts are termed outreach scholarship nesses, neighborhoods and communities, (Lerner & Miller, 1998). physical/ecological settings, and the socio- In other words, given the developmen- cultural, political, legal, moral, and economic tal systems perspective on which ADS is institutions of society. Together, bidirectional predicated, applied developmental scientists relations among these levels of the develop- assume the following: mental system necessitate systemic approaches to research, program and policy design, and There is an interactive relationship between science and application. Accordingly, the program and policy implementation. work of those who generate empirically The fourth principle of ADS emphasizes based knowledge about development and descriptively normative developmental pro- those who provide professional services or cesses and primary prevention and optimi- construct policies affecting individuals and families is seen as reciprocal in that research zation, rather than remediation. Applied and theory guide intervention strategies and developmental scientists emphasize healthy the evaluation of interventions and policies and normative developmental processes and provides the bases for reformulating theory seek to identify the strengths and assets of and future research....As a result, applied developmental [scientists] not only dissemi- individuals, groups, and settings, rather than nate information about development to focusing on deficits, weaknesses, or prob- parents, professionals, and policymakers lems of individuals, families, or communities. working to enhance the development of Instead of dwelling on the problems faced by others, they also integrate the perspectives and experiences of these members of the people, applied developmental scientists aim community into the reformulation of theory to find combinations of individual and and the design of research and interventions. ecological assets associated with thriving (Fisher & Lerner, 1994, p. 7) among people (e.g., Benson, 1997; Benson, Leffert, Scales, & Blyth, 1998; Leffert et al., Given the theoretically predicated set of 1998; Scales, Benson, Leffert, & Blyth, 2000) principles defining ADS, it is clear that not and with the “5 Cs” of positive individual all possible realms of developmental science development: competence, confidence, con- would lend themselves to this view of schol- nection, character, and caring/compassion arship (e.g., genetic-reductionist approaches (Hamilton & Hamilton, 1999; Lerner, to human development would not fit 2002b; Little, 1993; Pittman, 1996). within this approach; for a more thorough The final principle of ADS is the appreci- discussion of this point, see Lerner, 2002b). ation of the bidirectional relationship It is useful, then, to discuss the dimensions between knowledge generation and knowl- of scientific work that are brought to the edge application. By acknowledging bidirec- forefront by an ADS perspective framed by tionality, applied developmental scientists developmental systems thinking.