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

Human development unfolds through distinct stages, each shaping our physical, emotional, and cognitive growth. Understanding these stages connects to psychology, social work, and even crime, highlighting how early experiences influence behavior and identity throughout life.

1. Prenatal development

   • Development occurs in three stages: germinal, embryonic, and fetal.
   • Critical periods for organ development and exposure to teratogens can impact health.
   • Genetic and environmental factors influence growth and development.

2. Infancy (birth to 2 years)

   • Rapid physical growth and brain development occur.
   • Sensory and motor skills develop, including reflexes and coordination.
   • Attachment to caregivers is crucial for emotional security.

3. Toddlerhood (2-3 years)

   • Language skills begin to emerge, with vocabulary expanding rapidly.
   • Independence increases, leading to exploration and autonomy.
   • Social interactions become more complex, including parallel play.

4. Early childhood (3-6 years)

   • Imaginative play is prominent, fostering creativity and social skills.
   • Development of basic motor skills and coordination.
   • Understanding of rules and social norms begins to form.

5. Middle childhood (6-11 years)

   • Cognitive abilities expand, including logical thinking and problem-solving.
   • Peer relationships become more important, influencing social development.
   • Self-concept and self-esteem begin to develop based on feedback from others.

6. Adolescence (12-18 years)

   • Identity exploration and formation are key tasks during this stage.
   • Physical changes due to puberty can impact self-image and social dynamics.
   • Moral reasoning and ethical considerations become more complex.

7. Early adulthood (18-40 years)

   • Focus on establishing intimate relationships and starting families.
   • Career development and pursuit of personal goals are significant.
   • Exploration of personal values and life direction continues.

8. Middle adulthood (40-65 years)

   • Reflection on life achievements and contributions to society.
   • Physical changes may include health concerns and aging.
   • Relationships with children and aging parents can shift dynamics.

9. Late adulthood (65+ years)

   • Cognitive decline may occur, but many maintain mental acuity.
   • Reflection on life can lead to feelings of fulfillment or regret.
   • Social connections and support systems are crucial for well-being.

10. Erikson's psychosocial stages

    • Eight stages of development, each with a psychosocial conflict to resolve.
    • Successful resolution leads to a healthy personality and social skills.
    • Stages span from trust vs. mistrust in infancy to integrity vs. despair in late adulthood.

11. Piaget's cognitive development theory

    • Four stages: sensorimotor, preoperational, concrete operational, and formal operational.
    • Children actively construct knowledge through interaction with their environment.
    • Each stage represents a different way of thinking and understanding the world.

12. Kohlberg's moral development theory

    • Three levels of moral reasoning: pre-conventional, conventional, and post-conventional.
    • Emphasizes the development of ethical principles and justice.
    • Moral reasoning evolves from self-interest to broader societal considerations.

13. Attachment theory

    • Early bonds with caregivers shape emotional and social development.
    • Secure attachment leads to healthier relationships in adulthood.
    • Different attachment styles (secure, anxious, avoidant) influence behavior.

14. Freud's psychosexual stages

    • Five stages: oral, anal, phallic, latency, and genital.
    • Each stage focuses on pleasure from different body areas and conflicts.
    • Unresolved conflicts can lead to personality issues in adulthood.

15. Language development

    • Rapid vocabulary growth occurs in early childhood.
    • Critical periods exist for language acquisition and fluency.
    • Social interaction plays a key role in language learning.

16. Social development

    • Development of social skills and understanding of social norms.
    • Peer relationships become increasingly important throughout childhood.
    • Socialization influences identity and self-concept.

17. Emotional development

    • Recognition and expression of emotions evolve from infancy to adulthood.
    • Emotional regulation skills develop over time.
    • Early experiences shape emotional responses and coping mechanisms.

18. Physical development

    • Growth patterns vary across different stages of life.
    • Motor skills develop from reflexive actions in infancy to complex movements in adulthood.
    • Aging brings physical changes that can affect health and mobility.

19. Identity formation

    • Exploration of personal values, beliefs, and goals, especially during adolescence.
    • Influenced by social, cultural, and familial factors.
    • Successful identity formation leads to a strong sense of self.

20. Cognitive development

    • Involves changes in thinking, problem-solving, and decision-making abilities.
    • Influenced by experiences, education, and social interactions.
    • Continues to evolve throughout life, with potential for growth in late adulthood.