Most of his inspiration about intellectual and cognitive abilities came by observation of children. He described the four conceptual stages; the sensorimotor stage (birth to 2 years) at this stage, the child cannot form mental representations of objects that are outside his immediate view, so his intelligence develops through his motor interactions with his environment. The preoperational stage ( 2 to 6/7 years) this is the stage where true "thought" emerges. Children are able to make mental representations of unseen objects, but they cannot use deductive reasoning. The concrete operations stage ( 6/7 years to 11years) demonstrate conservation of number, and can differentiate their perspective from that of other people. Formal operations stage (11/12 to adult) is ability to think abstractly.
Jean Piaget also described that humans organize patterns of thought and behaviour that reflects those processes such as how we acquire, organize, and use what we learn. This involves three elements called schemes, adaptation and equilibration.
Schema defines as a set of mental and physical actions and also as unit of knowledge including objects and abstract concept to understand the world and to response to situations. Adaptation is the process of taking in new information into previous existing knowledge which is assimilation. Another part of adaptation is accommodation which involves changing or altering the existing knowledge to create new idea and information.Equilibrium is balance between assimilation and accommodation by mastering the new information through assimilation and accommodation. Once the new information is acquired the process of assimilation with the new schema will continue until the next time we need