What are Piaget's four stages of cognitive development (in order)?	Sensorimotor (0-2), Preoperational (2-7), Concrete Operational (7-11), Formal Operational (12+).
What is object permanence and when does it develop?	The understanding that objects continue to exist even when out of sight. Develops during the sensorimotor stage, around 8 months.
What is egocentrism in Piaget's theory?	A preoperational child's inability to see the world from another person's perspective, demonstrated by the three-mountain task.
What is conservation in Piaget's theory?	The understanding that quantity remains the same despite changes in shape or appearance. Children master this in the concrete operational stage.
What are Erikson's first three psychosocial stages?	Trust vs. Mistrust (infancy), Autonomy vs. Shame and Doubt (toddlerhood), Initiative vs. Guilt (preschool).
What is Erikson's identity vs. role confusion stage?	The adolescent stage in which teens work to develop a sense of self and personal identity. Failure leads to role confusion and a weak sense of self.
What are the three types of attachment identified by Ainsworth?	Secure attachment, insecure-avoidant attachment, and insecure-anxious/ambivalent attachment, identified through the Strange Situation experiment.
What is Harlow's attachment research?	Harlow showed that infant monkeys preferred a soft cloth 'mother' over a wire one with food, demonstrating that contact comfort is more important than nourishment for attachment.
What are Kohlberg's three levels of moral development?	Preconventional (self-interest), Conventional (social approval and law/order), Postconventional (universal ethical principles).
What are teratogens?	Harmful agents (drugs, viruses, chemicals) that can cross the placental barrier and cause birth defects during prenatal development.
What are the three stages of prenatal development?	Germinal (0-2 weeks, zygote implants), Embryonic (2-8 weeks, major organs form), Fetal (9 weeks-birth, growth and maturation).
What is the nature vs. nurture debate?	The longstanding controversy over the relative contributions of genetics (nature) and environment/experience (nurture) to development. Most psychologists now see them as interacting.
What is a critical period in development?	A time window during which certain experiences must occur for normal development. Example: language acquisition is easiest before puberty.
What is the difference between assimilation and accommodation?	Assimilation is interpreting new experiences using existing schemas. Accommodation is modifying existing schemas to incorporate new information.
What is Vygotsky's zone of proximal development (ZPD)?	The gap between what a child can do independently and what they can do with guidance. Learning occurs best within this zone through scaffolding.
What is temperament?	An infant's inborn behavioral style and emotional reactivity. Thomas and Chess identified three types: easy, difficult, and slow-to-warm-up.