Piaget's Four Stages of Cognitive Development
Your brain doesn't just grow bigger as you age - it actually develops completely different ways of thinking! Piaget identified four stages that everyone goes through, each with unique characteristics that explain how children understand their world.
The sensori-motor stage 0−2years is when babies learn through their senses and physical exploration. The biggest breakthrough here is object permanence around 12 months - realising that things still exist even when you can't see them (like when someone plays peekaboo!).
During the pre-operational stage 2−7years, children develop language but still think quite differently from adults. They experience animism (believing objects have feelings) and egocentrism (only seeing things from their own point of view).
The concrete operational stage 7−11years brings major thinking improvements. Children develop decentration (handling multiple pieces of information), reversibility (understanding changes can be undone), and conservation (knowing that changing appearance doesn't change quantity). Finally, the formal operational stage 11+years allows abstract thinking and problem-solving without needing physical objects.
Key Insight: These stages help explain why you might have believed your teddy bear had feelings as a child, but can now think about complex abstract concepts!
Piaget also explained how we process new information through schemas (mental storage systems), assimilation (fitting new info into existing schemas), and accommodation (creating new schemas when something doesn't fit).
However, critics argue the theory is too reductionist and rigid, ignoring individual differences and focusing too heavily on logical thinking whilst overlooking creativity and other factors like family upbringing.