Key Concepts in Developmental Psychology

Conservation

the principle that properties such as mass, volume, and number remain the same despite changes in the forms of objects

Egocentrism

in Piaget's theory, the preoperational child's difficulty taking another's point of view

Concrete Operational Stage

in Piaget's theory, the stage of cognitive development (from about 7 to 11 years of age) at which children can perform the mental operations that enable them to think logically about concrete (actual, physical) events

Formal Operational Stage

in Piaget's theory, the stage of cognitive development (normally beginning about age 12) at which people begin to think logically about abstract concepts

Scaffold

in Vygotsky's theory, a framework that offers children temporary support as they develop higher levels of thinking

Theory of Mind

people's ideas about their own and others' mental states - about their feelings, perceptions, and thoughts, and the behaviors these might predict

Ecological Systems Theory

a theory of the social environment's influence on human development, using five nested systems ranging from direct to indirect influences

Stranger Anxiety

the fear of strangers that infants commonly display, beginning by about 8 months of age

Attachment

an emotional tie with others; shown in young children by their seeking closeness to caregivers and showing distress on separation

Imprinting

the process by which certain animals form strong attachments during early life

Strange Situation

a procedure for studying child-caregiver attachment; a child is placed in an unfamiliar environment while their caregiver leaves and then returns, and the child's reactions are observed

Secure Attachment

demonstrated by infants who comfortably explore environments in the presence of their caregiver, show only temporary distress when the caregiver leaves, and find comfort in the caregiver's return

Insecure Attachment

demonstrated by infants who display a clinging, anxious attachment; an avoidant attachment that resists closeness; or a disorganized attachment with no consistent behavior when separated from or reunited with caregivers

Temperament

a person's characteristic emotional reactivity and intensity

Basic Trust

according to Erik Erikson, a sense that the world is predictable and trustworthy; said to be formed during infancy by appropriate experiences with responsive caregivers

Self-Concept

all our thoughts and feelings about ourselves, in answer to the question, "Who am I?"

Identity

our sense of self; according to Erikson, the adolescent's task is to solidify a sense of self by testing and integrating various roles

Social Identity

the "we" aspect of our self-concept; the part of our answer to "Who am I?" that comes from our group memberships

Intimacy

in Erikson's theory, the ability to form close, loving relationships; a primary developmental task in young adulthood

Emerging Adulthood

a period from about age 18 to the mid-twenties, when many persons in prosperous Western cultures are no longer adolescents but have not yet achieved full independence as adults

Social Clock

the culturally preferred timing of social events such as marriage, parenthood, and retirement