
One of the best persons in the field of Psychology is Jean Piaget. He talks about the evolution of the human being through stages what correlated with age. This stages are four: sensorimotor period (years 0 to 2); preoperational period (years 2 to 7); concrete operational period (years 7 to 12) and
formal operational period (years 12 and up).
This important author talks about the personality as a construction where the biological and the enviromental factors are mixed to become in a didtintive way that defined the development of the life. The human being is in permanent evolution and transformation. In those constant changes there are two important process that the individuals experiments: assimilation and to fit. The first process consist of the absorption of the external stimules at the internal structures of the human; the second process has the opossite direction, and it consists of the modification of individual structures to the external stimulus. In those two process is the adaptation of the human being and their more or less grade of integration at the world. I like his theory of cognitive development, because it proposes that there are distinct and increasingly stages of mental representation that children pass through on their way to an adult level of intelligence.