Summary

Here are some of the main points we've covered:

1. Piaget observed that children's thinking changes systematically as they grow older. These changes occur through the processes of assimilation and accommodation.

2. Children move through a series of four stages of intellectual growth from infancy to the teen years:

Sensorimotor Period -- birth to age 2
Preoperational Period -- ages 2-6
Concrete Operations Period -- ages 7-11
Formal Operations Period -- ages 12 and above