Piaget's Sensorimotor and Preoperational Stages
In this sub stage, the child learns and gains experience through inborn reflexes (sucking, grasping).
Primary circular reactions
6 weeks to 4 months
This stage is characterized by building new schemas. Actions that are pleasurable are circular, they are repeating. Reflexes are refined and used to build complex actions (thumb sucking, putting hands in mouth, opening and closing hands).
Secondary circular reactions
Actions are related to the outside world. Child begins to notice connections between own actions and effects they have on the outside world. They also begin to imitate sounds and movements that they spontaneously perform and that are visible (pick up and drop toys, seeking for partially hidden objects and discontinuity in search when objects stop to be visible).
Coordination of secondary circular reactions
8 to 12 months
Here, baby applies secondary circular reactions in process of solving problems. Schemes that are means are distinguished from the schemes that are recognized as goals. Their behavior is aimed towards goals. Object permanence is another achievement of this sub stage. They realize that physical objects exist even if they are no longer visible (if we hide stuffed animal behind us the baby will know that it still exists and where to search for it).
Tertiary circular reactions
12 to 18 months
Here we have creative behaviors that lead to new outcomes. Infants experiment to see what consequences will arise from these behaviors. Infants systematically imitate new actions of the models that were directly perceived. (baby drops things from different heights to see what will happen)
18 to 24 months
Baby discovers new ways for solving problems with the help of inner combining which can culminate in sudden understanding of situation. Child begins to form mental representations and use symbols. Deferred imitation emerges that allows infants to imitate someone else’s behaviors days after they have been observed (talk over toy telephone).
2 to 4 years
Child uses symbols and mental representations. Objects can be used to represent something else. Here infants can think about the objects that they do not see. Children exhibit egocentric point of views. Animism is another limitation of this sub stage.(pretended play, play with flat mirror as it were a comb)
4 to 7 years
In this sub-stage children show curiosity about the surrounding and ask questions, such as WHY. They already have some knowledge but they are unaware of the process they gained it. (questions such as “why the river flows” or “why the Sun rises” are very frequent)
Piaget, J. (1971). The theory of stages in cognitive development.