3.6. Major Theories of Development

• Sensorimotor Stage (0–2 yrs): Learning through actions. • Preoperational Stage (2–7 yrs): Symbolic thinking, egocentrism. • Concrete Operational Stage (7–11 yrs): Logical thought, conservation. • Formal Operational Stage (12+ yrs): Abstract and hypothetical reasoning.

Jean Piaget developed a theory of cognitive development that explains how children's thinking evolves over four stages:

1. Sensorimotor Stage (0–2 years): During this period, infants learn about the world primarily through their senses and actions. They interact with their environment by touching, mouthing, and manipulating objects.
2. Preoperational Stage (2–7 years): Children begin to use language and engage in symbolic play, but their thinking is still egocentric. They cannot easily see things from perspectives other than their own.
3. Concrete Operational Stage (7–11 years): At this stage, children start to think logically about concrete events. They understand the concept of conservation—that quantities remain the same despite changes in shape or appearance.
4. Formal Operational Stage (12 years and older): Adolescents learn to think abstractly and hypothetically. They can formulate and test hypotheses, as well as consider possibilities that don't exist in reality.

Imagine a toddler learning that their favorite toy can be hidden behind a couch (Sensorimotor). As they grow into preschoolers, they might play pretend with a stick, pretending it's a sword (Preoperational). By the time they're in elementary school, they can understand why pouring water from a short, wide cup into a tall, narrow one doesn't change the amount of water (Concrete Operational). Finally, a teenager can discuss philosophical concepts like 'what if humanity could live on another planet?' (Formal Operational), exploring ideas beyond immediate physical experiences.

• 8 stages of development, each with a key psychosocial conflict: a. Trust vs. Mistrust (Infancy) b. Autonomy vs. Shame and Doubt (Toddlerhood) c. Initiative vs. Guilt (Early Childhood) d. Industry vs. Inferiority (Middle Childhood) e. Identity vs. Role Confusion (Adolescence) f. Intimacy vs. Isolation (Young Adulthood) g. Generativity vs. Stagnation (Middle Adulthood) h. Integrity vs. Despair (Late Adulthood)

Erik Erikson proposed a theory of psychosocial development that identifies eight stages from infancy to adulthood, each characterized by a central conflict:

1. Trust vs. Mistrust (Infancy): Babies learn whether they can trust caregivers to meet their needs.
2. Autonomy vs. Shame and Doubt (Toddlerhood): Toddlers learn to assert independence, but if overly criticized, they may develop shame.
3. Initiative vs. Guilt (Early Childhood): Children begin initiating activities and exploring their surroundings; too much criticism can lead to guilt.
4. Industry vs. Inferiority (Middle Childhood): Children learn to work with others and develop a sense of competence or feel inferior if they struggle.
5. Identity vs. Role Confusion (Adolescence): Teens seek to find themselves and their place in society; failure can lead to confusion about one’s future.
6. Intimacy vs. Isolation (Young Adulthood): Young adults face the challenge of forming meaningful relationships or risk feeling isolated.
7. Generativity vs. Stagnation (Middle Adulthood): Adults need to create or nurture things that will outlast them (like children) or feel unproductive.
8. Integrity vs. Despair (Late Adulthood): Seniors reflect on their lives; success leads to feelings of fulfillment while failure results in regret.

Think about a selfie journey through life: as infants, we look to caregivers (Trust vs. Mistrust). As toddlers, we begin to dress ourselves and make choices (Autonomy vs. Shame). In school, we learn to work on team projects to feel skilled (Industry vs. Inferiority). In high school, we explore different identities like being a sporty or artistic student (Identity vs. Role Confusion). When looking back in adulthood, we seek close relationships (Intimacy) and think about how we can contribute to society (Generativity). Finally, during retirement, we reflect on our lives, celebrating achievements, or contemplating lost opportunities (Integrity vs. Despair).