Introduction to Psychology
Fields

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Adult development and aging

Adult development and aging studies psychological continuity and change through adulthood, including cognition, everyday functioning and differences between individuals.

Also called: psychology of aging

Core subfieldDevelopment

Type of entry
Core subfieldA long-standing main area of research in psychology. Types are editorial labels, not an official classification.
Cluster
Development and learningChange across life, learning, schooling and behavior analysis.
Sources opened
4 of 40 read as a full page, 4 as selected text or an abstract, 0 not verified.
Independent review
Admitted as writtencodex-core-repair-reviewer, 2026-10-21. 8 claims checked against 4 sources opened by the reviewer.

What it studies

Adult development and aging examines psychological continuity and change across the adult years. Research asks how cognition and psychosocial functioning develop, how individuals differ, and how experience and biological aging interact. It belongs within lifespan psychology while concentrating on adulthood. Psychological measurement and repeated observation distinguish the examples here from a general description of interdisciplinary gerontology.

History and people

Long-running studies helped make adult psychological development an empirical research program. The Seattle Longitudinal Study began in 1956 under founding director K. Warner Schaie. Sherry Willis became its co-director in 2005. In Germany, Paul B. Baltes established the Center for Lifespan Psychology in 1981 and jointly led the Berlin Aging Study, initiated in 1989, with Karl Ulrich Mayer. These dates identify projects and institutions rather than the field's birth.

People and documented roles

  • K. Warner Schaie. Founding director of the Seattle Longitudinal Study
    • Directed the project begun in 1956. [1]
  • Sherry Willis. Co-director of the Seattle Longitudinal Study
    • Became study co-director in 2005. [1]
  • Paul B. Baltes. Organizer of lifespan psychology research
    • Established the Center for Lifespan Psychology in 1981. [3]
  • Karl Ulrich Mayer. Original joint leader of the Berlin Aging Study
    • Jointly led the study initiated in 1989. [4]

These sources document institutional and research roles in two study programs. They do not establish a complete contributor list or a sole originator of adult development research.

Dated milestones

  • 1956Research report. Year.Seattle Longitudinal Study begins. [1]
  • 1981Institution built. Year.Center for Lifespan Psychology is established. [3]
  • 1989Research report. Year.Berlin Aging Study is initiated. [4]

Methods

The Seattle study uses a cohort-sequential longitudinal design, examining cognitive and psychosocial change across birth cohorts over the same age span. Its battery includes perceptual speed, verbal memory and everyday tasks, alongside selected personality, health and environmental measures. The Berlin study combines an age- and sex-stratified local sample with repeated interdisciplinary assessments, supporting comparisons between people and analyses of change within survivors.

Training and applications

Documented research settings include the Seattle project and the Center for Lifespan Psychology at the Max Planck Institute for Human Development. These were selected for their explicit psychological questions and study descriptions, checked for this profile. Measures of real-life tasks, health history and family environment connect cognitive research with everyday adult functioning. This research profile does not specify a clinical qualification or a licensing route.

Boundaries and limits

The Seattle sample originated in a regional health organization, while the Berlin study focused on advanced old age. Neither sample alone represents all adult populations. The center also studies childhood, illustrating the wider lifespan framework around adult research. Clinical assessment and treatment of older adults belong to the overlapping specialty of geropsychology. Project histories and institutional accounts provide examples rather than a complete international intellectual history.

Evidence behind the claims

  • The Seattle Longitudinal Study began in 1956 with K. Warner Schaie as founding director.

    History and peopleThe organization's own descriptionSource: [1]Where: Homepage, opening paragraph and director paragraph

  • Sherry Willis became Seattle Longitudinal Study co-director in 2005.

    History and peopleThe organization's own descriptionSource: [1]Where: Homepage, director paragraph

  • Paul B. Baltes established the Center for Lifespan Psychology in 1981.

    History and peopleThe organization's own descriptionSource: [3]Where: Introductory Overview, first sentence

  • The Berlin Aging Study was initiated in 1989 under Paul B. Baltes and Karl Ulrich Mayer.

    History and peopleThe organization's own descriptionSource: [4]Where: Opening paragraph

  • The Seattle study uses a cohort-sequential longitudinal design to examine cognitive and psychosocial change across birth cohorts.

    MethodsThe organization's own descriptionSource: [1]Where: Homepage, opening substantive paragraph

  • The Seattle battery includes perceptual speed, verbal memory and tasks intended to measure ecological validity.

    MethodsThe organization's own descriptionSource: [2]Where: The SLS Measurement Battery

  • The Berlin study combines an age- and sex-stratified local sample with longitudinal interdisciplinary assessments in advanced old age.

    MethodsThe organization's own descriptionSource: [4]Where: BASE-Charakteristika and Durchführung

  • The Center for Lifespan Psychology studies late adulthood and old age within a wider lifespan approach that also includes childhood.

    What it studiesThe organization's own descriptionSource: [3]Where: Introductory Overview, first paragraph

In the Psy101 course

This is course relevance only. It is not evidence for the historical or practice claims on this page.See the full course map.

Sources and inspection

4 of 4 sources were opened and read at the level shown. A source marked as not verified supports no claim on this page by itself.

  1. [1]
    Seattle Longitudinal StudyUniversity of Washington, undated. University page. Supports the history.Selected text readRead the substantive home-page description of cohort-sequential design, sampling, 1956 start and named directors; no linked papers inspected. Checked on October 21, 2026.
  2. [2]
    MeasuresUniversity of Washington, undated. University page. Supports the description of methods.Selected text readRead SLS Measurement Battery and Cognitive Ability Battery paragraphs; collapsed individual-measure links not opened. Checked on October 21, 2026.
  3. [3]
    Center for Lifespan PsychologyMax Planck Institute for Human Development, undated. University page. Supports the definition of the area.Selected text readRead introductory overview and first guiding proposition in the Research Report 2023-2025/26; no claim that this whole report was read. Checked on October 21, 2026.
  4. [4]
    Berliner Altersstudie (BASE)Max Planck Institute for Human Development, undated. University page. Supports the description of methods.Selected text readRead German introductory history, BASE-Charakteristika and Durchführung; paraphrases translated into English. Checked on October 21, 2026.

Independent source review: codex-core-repair-reviewer, 2026-10-21. Verdict: Admitted as written. Of 8 claims checked, 8 were supported as written, 0 were reworded and 0 were removed.