Cognition and Language

Piaget's Cognitive Development

Piaget's four stages: sensorimotor (0-2, object permanence), preoperational (2-7, egocentrism and failure of conservation), concrete operational (7-11, conservation and concrete logic), and formal operational (12+, abstract hypothetical reasoning). Children build schemas and update them by assimilation (fitting new information into an existing schema) versus accommodation (revising the schema itself).

Language Development

The universal sequence: babbling at 6-9 months, one-word holophrastic speech around 12 months, two-word telegraphic speech at 18-24 months ("want cookie"), then a grammar explosion from ages 2-5 producing complex sentences.

Problem Solving and Bias

An algorithm is a step-by-step guaranteed solution; a heuristic is a fast mental shortcut that trades accuracy for speed. High-yield errors include confirmation bias (seeking evidence that fits existing beliefs) and functional fixedness (inability to see new uses for familiar objects). Availability and representativeness heuristics explain many judgment errors under uncertainty.

Key Takeaways

• Piaget: sensorimotor, preoperational, concrete, formal -- know each stage's signature ability
• Assimilation fits data to schemas; accommodation revises the schema
• Language milestones: babbling, holophrastic, telegraphic, grammar explosion
• Heuristics are fast but biased; algorithms are slow but guaranteed