| For an overview of the stages of sensorimotor thought, it helps to group the six stages into pairs. The first two stages involve the infant’s responses to its own body. |
| Primary Circular Reactions |
| Stage One (birth to 1 month) | Reflexes: sucking, grasping, staring, listening |
| Stage Two (1–4 months) | The first acquired adaptations: accommodation and coordination of reflexesExamples: sucking a pacifier differently from a nipple; attempting to hold a bottle to suck it |
| The next two stages involve the infant’s responses to objects and people. |
| Secondary Circular Reactions |
| Stage Three (4–8 months) | Making interesting events last: responding to people and objectsExample: clapping hands when mother says “patty-cake” |
| Stage Four (8–12 months) | New adaptation and anticipation: becoming more deliberate and purposeful in responding to people and objectsExample: putting mother’s hands together in order to make her start playing patty-cake |
| The last two stages are the most creative, first with action and then with ideas. |
| Tertiary Circular Reactions |
| Stage Five (12–18 months) | New means through active experimentation:experimentation and creativity in the actions of the “little scientist”Example: putting a teddy bear in the toilet and flushing it |
| Stage Six (18–24 months) | New means through mental combinations: thinking before doing, new ways of achieving a goal without resorting to trial and error.Example: before flushing the teddy bear, hesitating because of the memory of the toilet overflowing and mother’s anger |