| Term | Definition |
| accommodation | The process pf adjusting existing ways of thinking to encompass new information, ideas, or objects |
| assimilation | The process by which new information is placed into preexisting categories |
| attachment | An active and intense emotional relationship between two people that endures over time |
| authoritarian | A parenting style that stresses unquestioning obedience |
| authoritative | A parenting style based on recognized authority or knowledge and characterized by mutual respect |
| childhood | The stage of life that follows infancy and spans the period from the second birthday to the beginning of adolescence |
| concrete-operational stage | According to Piaget, the stage of cognitive development during which children acquire the ability to think logically |
| conditional positive regard | An expression of esteem given only when an individual has exhibited suitable behavior |
| conservation | According to Piaget, the principle that the properties of substances remain the dame despite changes in their shape or arrangement |
| contact comfort | The satisfaction obtained from pleasant, soft stimulation |
| conventional moral reasoning | The level of moral development at which a person makes judgments based on conventional standards of right and wrong |
| critical period | a stage or point in development during which a person or animal is best suited to learn a new skill or behavior |
| developmental psychology | the branch of psychology that studies the physical, cognitive, and social changes that occur throughout the life cycle |
| egocentrism | In Piaget's theory, the inability of the preoperational child to understand another's point of view |
| formal-operational stage | According to Piaget, the stage of cognitive development during which people begin to think logically about abstract concepts |
| imprinting | The process by which animals form strong attachments during a critical period very early in life |
| infancy | In humans, the stage of life from birth to age two |
| maturation | developmental changes that occur as a result of automatic, genetically determined signals |
| object permanence | The awareness that people and objects continue tom exist even when they cannot be perceived |
| postconventional moral reasoning | According to Kohlberg, a level of moral development during which moral judgments are derived from a person's own moral standards |
| preconventional moral reasoning | According to Kohlberg, a level of moral development in which moral judgments are based on fear of punishment or desire for pleasure |
| preoperational stage | In Piaget's theory, the stage during which a child learns to use language but does not yet think logically |
| reflex | an automatic, unlearned response to a sensory signal |
| self-esteem | The value or worth that people attach to themselves |
| sensorimotor stage | According to Piaget, the stage during which infants know the world mostly in terms of their sensory impressions and motor activities |
| separation anxiety | Distress that is sometimes experienced by infants when they are separated from their primary caregivers |
| stranger anxiety | The fear of strangers that infants commonly display |
| unconditional positive regard | A consistent expression of esteem for the basic value of a person |