Child psychology is a branch of developmental psychology, dedicated to the exploration of patterns of mental development of the child. The main subject of analysis is driving causes and conditions for ontogenetic development of individual mental processes, including the formation of different types of a child behavior.
Child psychology, as a science of mental development of the child, originated as a branch of comparative psychology in the late 19th century. The starting point for systematic research on the psychology of the child is a work «Die Seele des Kindes» by Darwinian William Preyer. The work described the results of the Preyer’s daily observations on the development of his own son, paying attention to the development of his senses, motor skills, will, mind, and language. Despite the fact that the monitoring took place long before the Preyer’s book was published, Preyer’s undeniable priority was the study of the earliest years of the child and the introduction of the method of objective observation to child psychology, developed by analogy with the methods in the natural sciences. In modern terms, Peyer’s views are seen as naive, limited to the level of development of science of the 19th century. For example, he considered the mental development of the child as a version of the biological development. (However, strictly speaking, even today, there are hidden and explicit proponents of this idea...). Nevertheless, Preyer was the first who made the transition from introspective to objective study of the child psyche. Therefore, he is considered the founder of child psychology by the unanimous recognition of the psychologists.