Piaget’s theory of cognitive development includes four periods that are related to age and demonstrate specific categories of knowing and understanding.
- Sensorimotor (birth to 2): the infant develops the schema or action pattern for dealing with the environment
- 0-1 month: reflexes (sucking, rooting, grasping, crying) are primary
- 1-4 months: reflexive behavior is replaced by voluntary behavior, recognizing a stimulus and a response (primary circular reactions)
- 4-8 months: there is an intensification, with children developing a sense of causality, time, and personal separateness. They begin to imitate and show different affects. They develop a sense of object permanence between 6 and 8 months (secondary circular reactions)
- 9-12 months: this is a transitional stage with further intellectual development, including understanding that a hidden object is not gone. Children begin to behave with intention, to associate words and symbols (bye-bye) with events, and attempt to climb over obstacles
- 13-18 months: Newly acquired motor skills allow children to experiment and demonstrate the beginning of rational judgement and reasoning. Children further differentiate themselves from objects, understand cause and effect, but have little transfer ability. Children gain spatial awareness (tertiary circular reactions)
- 18-24 months: preparation for more complex intellectual activities. Children understand object permanence, begin to use language, and engage in domestic mimicry and sex-role behavior. They have some sense of time, but time is exaggerated.