Jean Piaget was born in Neuchâtel, Switzerland in 1896. He did his license and PhD on biology at the university of his hometown. It was his background on biology, and his interest on epistemology (the theory of knowledge), that made him want to find out how the mind comes to know knowledge, objects and concepts, which then lead him to study the development of children, especially his own. He observed, talked and listen to them, as well as other children, while he performed exercises to test his theories, studies that he then published and helped him create his theory.
Piaget's theory is called Intellectual Development, it is based on the maturation of the human. It was divided into four stages. These stages happen in between the ages of 0 and 15 years old. The first stage that happens between the age of 0 and 2, it is called Sensoriomotor Stage. Children start to differentiate themselves from objects and knows more about himself and where he is. Also a key think kids learn is that if parents or any object is outside of his sight it will continue to exist.
Pre-operational stage comes around 2-7 years of age, the most important thing happening in this stage is that children learn how to use language and by using this skill they represent objects by words or images. Children begin to use symbols to represent objects, also they don't have a