1.1 Psychology and Human Development
- Lifespan development is a subfield of the discipline of psychology; human development adds a multidisciplinary approach to the study of the lifespan.
- The study of lifespan development extends back to the ancient Greeks, through the Child Study Movement in the early 1900s, to today.
- Lifespan development as a scientific discipline is concerned with application—taking findings and putting them to use in people’s lives.
1.2 Themes of Development
- Lifespan development is especially interested in the timing of developmental events and their impact on development.
- Depending on the topic, development can occur continuously (smooth and gradual) or discontinuously (abrupt or sudden).
- Lifespan development addresses the nature and nurture question, which explores the sources of developmental change and the relative contributions of genetics and the environment.
- Critical periods are times when an experience is expected and necessary for development to occur. Sensitive periods are windows of time when certain experiences can lead to an individual’s ideal development.
1.3 Major Theories and Theorists
- Lifespan psychologists use many different theoretical perspectives to study development, including cognitive, biological and evolutionary, and behaviorist perspectives.
- Our understanding benefits from the overlap of these perspectives—that is, the theories do not necessarily compete with one another, but instead complement one another, leading to a more complete and holistic understanding of development.
- The perspectives have a range of emphasis from the biological to the environmental; each perspective has a view on the nature and nurture question.
- The behaviorist perspective has helped scientists identify important learning and behavior concepts including classical conditioning, operant conditioning, and observational learning.
- Theories from the cognitive perspective that have helped us understand various facets of development include psychosocial theory of development, stage theory of cognitive development, sociocultural theory of cognitive development, and information processing theory.
1.4 Contexts and Settings of Development
- The study of the individual across the lifespan has benefitted from an ecological systems model in which each system is made up of contexts (distinct environments) in which development can be influenced.
- Psychological research findings are often broken down and further analyzed by social sub-groupings including gender, sexual orientation, ethnoracial background, socioeconomic status, culture, and religion.
- A major concern for the field of lifespan development is to be more aware of the universality and generalizability of its research, and to make findings as applicable as possible to people from around the world. Criticism of research centered on participants exclusively from Western, Educated, Industrialized, Rich, and Democratic societies is summarized in the acronym “WEIRD.”
1.5 Lifespan Development as a Science: Research Methods
- Psychological science has many scientific tools to explore developmental questions.
- These tools include naturalistic observation, case studies, correlational studies, experiments, natural experiments, and topic-specific apparatuses.
- Developmental researchers can choose a number of developmental research designs—cross-sectional, longitudinal, and cross-sequential.
- Ethical considerations guide all scientific research, especially when studying humans. A set of ethical principles operates in developmental research.
- Informed consent is a key requirement for psychological research.