development unit ap psychology 2025

teratogens

agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm.

rooting reflex

an automatic, unlearned response of a newborn to a gentle stimulus (e.g., the touch of a finger) applied to the corner of the mouth or to the cheek, in which the infant turns their head and makes sucking motions

critical period

an optimal period early in the life of an organism when exposure to certain stimuli or experiences produces normal development.

imprinting

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

menarche

the first menstrual period

spermarche

the first ejaculation

menopause

the time of natural cessation of menstruation; also refers to the biological changes a woman experiences as her ability to reproduce declines.

sensorimotor stage

in Piaget’s theory, the stage (from birth to nearly 2 years of age) at which infants know the world mostly in terms of their sensory impressions and motor activities.

object permanence

the awareness that things continue to exist even when not perceived.

preoperational stage

in Piaget’s theory, the stage (from about 2 to 6 or 7 years of age) at which a child learns to use language but does not yet comprehend the mental operations of concrete logic.

conservation

the principle (which Piaget believed to be a part of concrete operational reasoning) that properties such as mass, volume, and number remain the same despite changes in the forms of objects.

animism

a belief that inanimate objects are alive or have lifelike feelings and motivations

egocentrism

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

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

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.

zone of proximal development

the zone between what a child can and can’t do — it’s what a child can do with help

phoneme

in a language, the smallest distinctive sound unit

morpheme

in a language, the smallest unit that carries meaning; may be a word or a part of a word (such as a prefix).

grammar

in a language, a system of rules that enables us to communicate with and understand others. Semantics is the language’s set of rules for deriving meaning from sounds, and syntax is its set of rules for combining words into grammatically sensible sentences.

overgeneralization

the process of extending something beyond the circumstances to which it actually applies. It is a common linguistic tendency of young children to generalize standard grammatical rules to apply to irregular words (e.g., pluralizing foot to foots)

ecological systems theory

a theory of the social environment’s influence on human development, using five nested systems (microsystem; mesosystem; exosystem; macrosystem; chronosystem) ranging from direct to indirect influences.

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 either a clinging, anxious attachment or an avoidant attachment that resists closeness.

separation anxiety

the normal apprehension experienced by a young child when away (or facing the prospect of being away) from the person or people to whom they are attached (particularly parents).

contact comfort

the positive effects experienced by infants or young animals when in close contact with soft materials.

imaginary audience

the belief of an adolescent that others are constantly focusing attention on them, scrutinizing behaviors, appearance, and the like

personal fable

a belief in one’s uniqueness and invulnerability, which is an expression of adolescent egocentrism and may extend further into the lifespan

social clock

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