It should be noted that the notion that "childhood" is separate from "adulthood" is distinctively modern and mostly a product of Western society. Most childhood studies reveal that the role children play in society has shifted significantly in modern times. The historian, Philippe Aries, argues that children were viewed as "miniature adults" during the medieval ages and allowed to perform many of the same activities as adults. While some theorists have argued the validity of Aries's concept, it is a certainty that the labor reforms made in response to poor child worker conditions during the Industrial Age helped to establish differences between adults and children. In addition, due to recent studies, particularly The Six Culture Project, which examined the role children played in societies outside of Western culture, researchers have discovered that the notion of children as "not ready" for adulthood is also a localized construct. In African cultures, children played with toys like Western children, but in a type of rehearsal for the various activities performed by adults including marriage, child caring, animal hunting, and hut building. Thus, the term "childhood" is greatly conditioned by social and cultural factors.
Perhaps the four most common theories which have arisen about childhood and most deeply embedded themselves in Western thought are: Plato's rationalistic approach, the Christian notion of "original sin," John Locke's belief in tableau rasa, and Rousseau's idea of the "noble savage". While these theories were not designed specifically for the focus of childhood research, they have managed to secure themselves in the subconscious philosophical, religious and societal beliefs of many Westerners. Although these ideas have many unique points, they all share several important aspects including: the belief that all children are born with the same moral conditions, the assumption that children are "less developed" than adults, and the notion that children are conditioned to grow into adults through their interactions with society. Additionally, each theory aids in creating a power struggle between adults, who are seen as powerful, and children, who are treated as subservient to adults. Some child theorists believe that the creation of this power struggle creates a significant barrier in understanding "childhood."
Plato is responsible for the development of rationalism, a belief which stresses that idea that humans are born with an innate sense of knowledge. Throughout Plato's Dialogues, which have become a corner stone for Western philosophy, Plato attempts to reveal and clarify exactly what elements of knowledge and stresses that all humans are born with the same senses of love, beauty, and truth. This theory creates a power struggle which greatly stresses the notion that children are "less developed" than adults because they have had less opportunity to realize the "true" sources of knowledge in the world. Thus, childhood researchers who believe these ideas often find themselves assuming that they possess more knowledge about the inner workings of the world than children.
Christianity proposes the idea that children are born with "original sin", or in an innate state of evil due to the "original" sin of Adam and Eve. As such, it