Developmental systems theorists argue –Genetic and environmental factors are fused in development –There are bidirectional influences between genetic/biological factors within the individual and all levels of the environment

Developmental Systems Theories Process of development involves bidirectional relations occurring over time across multiple levels of organization –Levels of organization include those within the individual (e.g., biological) and outside the individual (e.g., societal, cultural) –Levels are “fused” or integrated in development

General Characteristics: –Relative Plasticity of Development Potential for systematic change exists across the lifespan Change can be effected by entering the developmental system at any of its levels Change is constrained by past development and current contextual conditions (therefore relative)

–Integration or fusion of multiple levels of organization involved in development The appropriate unit of analysis is “relational”— relations between variables at different levels of organization, rather than variables at a single level Contrasts with “unilevel” models of development (e.g., nature OR nurture)

–Development within a historical/temporal context History = Change over time History is a level of organization that is fused/integrated with all other levels –Thus, variables from all levels of organization undergo change over time Requires measures and designs that are “change-sensitive” –Longitudinal designs –Multiple cohorts

–Focus on diversity in development Changes that are seen within one historical period (or time of measurement) and with one set of variables may not be seen at other points in time Research should utilize diverse samples, diverse methodologies, and multiple measurements over time

Bronfenbrenner’s Bioecological Theory Development of an individual occurs within a set of nested contexts or levels The individual and his/her characteristics is at the center of these levels –Individual characteristics include gender, temperament, and other biologically based characteristics

Figure 9.4 The bioecological model Siegler, DeLoache and Eisenberg: How Children Develop, Second Edition Copyright © 2006 by Worth Publishers

Microsystem: The immediate environments that a child directly experiences and participates in –Exs: family, child care, school, peer group Mesosystem: The interconnections among the environments in the child’s microsystem –Ex: relations between family and peers

Exosystem: Environments which the child does not directly experience but which affect his/her development indirectly –Ex: parents’ workplace Macrosystem: Level involving culture, societal institutions, and public policy –Ex: laws/policies concerning parental leave from work

Chronosystem: Time –Includes time over days, weeks, months, and years

Process-Person-Contexts-Time (PPCT Model) Proximal Processes Development occurs through processes of “progressively more complex reciprocal interaction between an active... [individual] and the persons, objects, and symbols in its immediate external environment” (Bronfenbrenner, 2006)

Such interactions must occur on a fairly regular basis over extended periods of time to be effective in promoting development –Exs: comforting an infant, playing with a young child, child-child activities, group or solitary play, reading, learning new skills, athletic activities, problem-solving For children, participation in such interactions over time leads to the knowledge/skills and motivation to engage in such activities with others and independently Proximal processes are bidirectional Proximal processes (within the microsystem) are the “engines of development”

Proximal processes vary systematically due to –Person (individual characteristics) –Contexts (immediate and more remote environments—micro-, meso-, exo-, and macrosystems) –Time (stability of proximal processes over time as well as societal changes during the life course and the historical period in which an individual lives)

Interdependencies among the four components of the model –“In ecological research, the principal main effects are likely to be interactions”