the field that studies physical, cognitive, and psychosocial changes across the life span. 21, 106
the scientific study of age-related changes throughout the human life span.
the branch of psychology that studies the social and mental development of children
the branch of psychology that studies physical, cognitive, and social change of humans throughout their life cycle. Some argue that developmental psychologists study changes over time which all psychologists study, not just developmentalists. However, the difference is that the topics studied by developmental psychologists revolve around the maturation and aging process; what affects it and what it affects. For example, a developmental psychologist and myself may each conduct a study addressing how children of different ages perform on a particular test. The developmental Psychologist would be concerned with the differences between the age groups, why they performed differently, what developmental issues may be the causal factors in the differences, etc., while I may explain the differences in terms of the test, not the developmental differences of the children (i.e., the test is age appropriate, can we use it on people of other ages, what does having an age difference mean on whatever the test actually measured, etc.).
Systematic and scientific study of changes in human behaviors and mental activities over time.
Developmental psychology, also known as Human Development, is the scientific study of progressive psychological changes that occur in human beings as they age. Originally concerned with infants and children, and later other periods of great change such as adolescence and aging, it now encompasses the entire life span. This field examines change across a broad range of topics including motor skills and other psycho-physiological processes, problem solving abilities, conceptual understanding, acquisition of language, moral understanding, and identity formation.