From the mid-nineteenth century, the scientific study of child development emerged. Strongly influenced by evolutionism, the intelligence of children and young adults was hierarchized in stages, as was the case with other animal species. In the early twentieth century, through the works of, among others, Sigmund Freud, Alfred Binet, James Baldwin, Henri Wallon, Lev Vygotsky, Jean Piaget, Erik Erikson, etc., developmental psychology changes.
Two lines of research are established. On the one hand, the “ontogenesis” of cognitive development, seen as a response of individual adaptation to the environment or context of the individual; and on the other hand, by a deeper study of mental and brain operations, as organism or biotic system.
As invariable, the time factor continues to serve as an indicator of change. From the middle of the twentieth century, developmental psychology focuses mainly on the process in childhood and adolescence, leaving studies on aging and memory to the second line of research.
The psychology of education is associated with the line of studies on developmental psychology based on the evolution of states of cognitive maturity. Changes are categorized according to time scales, defining the types of mental operations that can be developed.
The educational processes should be adjusted to these categories.
In the psychology of education is a general approach to cognitive learning conditions and affective maturity for the acquisition of certain general and common skills to groups. On the other hand, the absence of standard operations or deviations from the norm gives rise to specific studies on disabilities and remedies. Deviations that may occur in the functions of language, hearing, affect, abstract operations, visual or motor functions.
More recently, approaches to psychology have tended to consider the idea of linear progress in the acquisition of skills and abilities, to consider that the educational process is a complex one that takes place as a function of the environment and individuals in different conditions. There is a consensus that children in a stable environment learn the relevant skills regardless of order (from simple to complex), although one must be aware of regressions, blockages or stagnation and their particularities.