Stages of Human Development to Know for AP Psychology (2025) (AP)

Prenatal development

encompasses the stages a human undergoes before birth, progressing through three main phases.

Germinal Stage (0-2 weeks)

Begins at conception, with the fertilized egg becoming a zygote and attaching to the uterine wall.

Embryonic Stage (3-8 weeks)

Major organs and body systems develop; critical period for the impact of teratogens (e.g., drugs, alcohol) which can cause birth defects.

Fetal Stage (9 weeks-birth)

Continued growth and development, with the maturation of organs and physical characteristics.

Infancy

is a period of rapid physical and neurological development, where sensory, motor, and emotional foundations are established.

Physical Growth

Infants double their birth weight by 5-6 months and triple it by one year.

Attachment

Infants form emotional bonds with caregivers, critical for emotional security and social development.

Motor Skills

Basic reflexes (grasping, rooting) evolve into voluntary movements like sitting, crawling, and walking.

Toddlerhood

marks a period of increasing independence, language acquisition, and initial social skills.

Language

Vocabulary grows rapidly, often resulting in a "vocabulary explosion."

Autonomy

Toddlers begin asserting independence, seeking to explore and make choices.

Social Interaction

Parallel play emerges, where toddlers play alongside each other but not directly with one another.

Early Childhood

 A stage marked by the expansion of imaginative play, improved motor skills, and early social understanding.

Imaginative Play

Fosters creativity, problem-solving, and social skills through pretend scenarios.

Motor Skills

Gross motor skills (running, jumping) and fine motor skills (drawing, dressing) develop.

Social Norms

Children begin to understand rules, fairness, and cooperative play.

Middle Childhood

A stage characterized by cognitive, social, and emotional growth, as well as the development of self-concept.

Adolescence

A period of significant physical, social, and emotional changes, including identity exploration.

Early Adulthood

focuses on establishing intimate relationships, career building, and setting personal goals.

Middle Adulthood

A stage marked by reflection on achievements, shifts in family dynamics, and physical aging.

Late Adulthood

Involve cognitive changes, reflection on life, and the importance of social connections.

Erikson's Psychosocial Stages

Theory suggests that each stage of life presents a unique psychosocial conflict that affects personality development.

Trust vs. Mistrust

The conflict in infancy, where consistent caregiving fosters trust, while inconsistent care may lead to mistrust.

Autonomy vs. Shame and Doubt

Occurs in toddlerhood, focusing on a child's ability to assert independence and self-control.

Identity vs. Role Confusion

A central issue in adolescence, involving exploration of personal values and goals to form a cohesive sense of self.

Integrity vs. Despair

The final conflict in late adulthood, where individuals reflect on their life with a sense of fulfillment or regret.

Piaget's Cognitive Development Theory

Theory posits that children go through four stages of cognitive development, each marked by distinct ways of thinking and understanding the world.

Schema

A mental framework or concept that helps individuals organize and interpret information.

Assimilation

The process of incorporating new experiences into existing schemas.

Accommodation

The process of modifying existing schemas to incorporate new information.

Sensorimotor Stage (0-2 years)

Infants learn through sensory experiences and movement; develops object permanence (understanding that objects exist even when not seen).

Preoperational Stage (2-7 years)

Symbolic thinking and imagination emerge, but thinking is egocentric, meaning children have difficulty understanding perspectives other than their own.

Concrete Operational Stage (7-11 years)

Children develop logical reasoning for concrete, tangible concepts but struggle with abstract ideas.

Formal Operational Stage (12+ years)

Abstract reasoning, problem-solving, and hypothetical thinking become possible.

Kohlberg's Moral Development Theory

describes the progression of moral reasoning through three levels, each marked by different motivations and ethical principles.

Moral Reasoning

The thought process individuals use to determine what is right or wrong.

Pre-Conventional Level

Morality based on self-interest, often with an aim to avoid punishment or gain rewards.

Conventional Level

Morality based on societal rules and gaining approval from others; focuses on conformity and maintaining social order.

Post-Conventional Level

Morality based on ethical principles and personal values that may transcend laws and social rules.

Attachment Theory

suggests that early relationships, particularly with caregivers, are foundational for emotional and social development.

Attachment Styles

Patterns of behavior in relationships that stem from early attachment experiences with caregivers.

Secure Attachment

Characterized by confidence in caregiver availability and a balanced approach to dependence and exploration.

Anxious Attachment

Characterized by clinginess or dependency due to inconsistent caregiving.

Avoidant Attachment

Marked by emotional distance and self-reliance due to unavailable or dismissive caregivers.

Separation Anxiety

Emotional distress shown by infants when separated from primary caregivers, indicating attachment formation.

Freud's Psychosexual Stages

personality develops through five stages, each focused on a different erogenous zone or pleasure area.

Erogenous Zones

Body areas that are particularly sensitive to stimulation and are associated with each developmental stage (e.g., mouth, anus).

Fixation

A persistent focus on an earlier stage due to unresolved conflicts, which can affect personality and behavior in adulthood.

Oedipus Complex

A term for a child’s feelings of desire for the opposite-sex parent and jealousy toward the same-sex parent, typically occurring in the phallic stage.

Oral Stage (0-1 year)

Pleasure centers on the mouth, through activities like sucking and eating.

Anal Stage (1-3 years):

Pleasure focuses on bowel and bladder control, with a central conflict around toilet training.

Phallic Stage (3-6 years):

Focus on the genital area; children may develop the Oedipus or Electra complex.

Latency Stage (6-puberty):

Sexual impulses are repressed, with energy directed to social and intellectual pursuits.

Genital Stage (puberty onward)

Sexual impulses re-emerge, leading to mature romantic relationships.

Language Development

The process through which individuals learn to understand and communicate through spoken or written language.

Phonemes

The smallest units of sound in a language, such as consonants and vowels.

Syntax

The set of rules that govern sentence structure and word order.

Social Interaction Theory

The theory that language develops through social interactions and is influenced by caregivers' feedback and interaction.

Social development

refers to the progression of social skills, understanding of social norms, and forming relationships.

Emotional Development

 is the process by which individuals learn to recognize, express, and regulate emotions.

Physical Development

 Refers to the changes in body structure, motor skills, and health that occur throughout the lifespan.

Identity Formation

 The development of a cohesive sense of self, particularly prominent in adolescence as individuals explore their values, beliefs, and goals.

Cognitive Development

Refers to changes in thinking, problem-solving, and decision-making abilities across the lifespan.

Metacognition

Awareness and understanding of one’s own thought processes, essential for self-directed learning and growth.

Crystallized Intelligence

Knowledge and skills accumulated over a lifetime, often remaining stable or improving with age.

Cognitive Flexibility

The ability to adapt thinking in response to changing goals or environmental demands, critical in problem-solving.

Fluid Intelligence

The ability to solve new problems and think abstractly, typically peaking in young adulthood and slowly declining with age.