3.4 Cognitive Development Across the Lifespan

Cognitive development theories explain how our thinking evolves from infancy to adulthood. Piaget's stages describe how children's mental frameworks grow, while Vygotsky emphasizes social learning and cultural context.

As we age, our accumulated knowledge typically increases, but abstract reasoning may decline. Some older adults experience dementia, with Alzheimer's being the most common cause of severe cognitive decline.

Piaget's cognitive development theory

Schemas in Piaget's theory

Kids build mental frameworks called schemas to make sense of the world. These schemas are flexible and change through two main processes:

• Assimilation: fitting new info into existing schemas
• Accommodation: changing or creating new schemas when the old ones don't work

This happens gradually and sometimes in "aha!" moments as kids interact with their environment.

Sensorimotor stage

This stage is from birth to about age 2. Babies learn mostly through their senses and physical actions.

The big breakthrough here is object permanence:

• Newborns think things disappear when they can't see them (peekaboo, but you're literally gone from the earth)
• Around 8 months, babies begin searching for partially hidden objects
• By 18-24 months, infants fully understand that objects exist even when completely out of sight

Preoperational stage

From ages 2-7, kids start using symbols and language to represent their world. You'll see a lot of pretend play as they flex their growing symbolic muscles. During this period, children begin developing theory of mind - the understanding that others have different thoughts and beliefs than their own.

Some limitations during this time:

• Don't get conservation
• Can't mentally reverse actions
• Think everything is alive (animistic thinking)
• See things only from their perspective (egocentric)

Concrete operational stage

Children develop logical thinking about concrete situations between ages 7 and 11. This represents a major shift in cognitive ability, as they master several key concepts:

• Conservation of number, mass, and volume
• Reversibility of actions
• Classification and seriation
• Spatial reasoning

While their thinking becomes more logical, they still struggle with abstract concepts and hypothetical situations.

Formal operational stage

The final stage of cognitive development begins around age 12 and continues through adulthood. Abstract thinking emerges as the hallmark of this stage.

Key characteristics include:

• Systematic problem-solving
• Abstract reasoning
• Hypothetical thinking
• Understanding of complex scientific concepts

Not everyone reaches the full potential of formal operational thinking, and development can vary significantly among individuals.

Vygotsky's social learning theory

Vygotsky viewed cognitive development as inherently social, emphasizing the role of culture and interaction in learning. His theory focuses on how children learn through social relationships and cultural context.

The Zone of Proximal Development (ZPD) is central to his theory:

• Represents the gap between what a child can do alone and with help
• Learning occurs most effectively within this zone
• Adults and peers provide scaffolding to help bridge this gap

Cultural tools and language play crucial roles in cognitive development, shaping how children think and learn.

Adult cognitive changes

Cognitive abilities change throughout adulthood in different ways. While some abilities decline, others remain stable or even improve with age.

Key patterns in adult cognitive development:

• Crystallized intelligence typically increases or remains stable
• Fluid intelligence shows gradual decline
• Processing speed generally decreases
• Memory changes vary by type

Dementia represents a significant deviation from normal cognitive aging:

• Affects multiple cognitive domains
• Interferes with daily functioning
• Alzheimer's disease is the most common form
• Early detection and intervention can help manage symptoms