First let's define which are these theories and who proposes them. The most widely-used theory for the purposes of modern education is the cognitive model of development proposed by Jean Piaget. In the field of education, the idea of "age appropriateness" rules all decision making processes, from the purchase of materials, to the creation of assessment tools. Jean Piaget was who proposed the idea of "stages" based on physical and psychological development. Both types of development deeply influence cognition, and the expansion of all brain processes. Later on, they interconnect and depend on each other as the individual matures and ages. According to Piaget the stages of development are:
- The Sensorimotor Stage (birth- 2yrs old- Main development: child discovering his world)
- The Preoperational Stage (2yrs-7yrs old- Main development: language development, egocentrism, conservation)
- The Concrete Operational Stage (7yrs- 11yrs old, Main development: inductive logic, reversibility)
- The Formal Operational Stage (11yrs old to adulthood) Main development: deductive logic, abstract thoughts, systematic problem solving)
As you can see, a lot of the tenets of Piaget's theory resonate with modern day school curricula and curriculum standards. Granted, Piaget did not put forth his theory to change the field of pedagogy. It was the researchers in education who realized that Piaget's theory applies greatly toward individual academic success because it is the first theory of its kind to declare that there should be preparedness based on age, maturity, and schema, prior for it to be any learning to be had.
Sigmund Freud's Psychoanalytic theory of personality development, or the Psycho-dynamic theory is also based on cognitive and behavioral development with emphasis on the conscious and the subconscious. In his theory, the major tenet is that the ‘id’, the ‘ego’ and the ‘superego’ are in a constant struggle with each other to determine our role within situations. Id is the "basic beast" in all of us, driven by sex, hunger, and other bio-psychological needs. This "inner monster" is checked and monitored by our Superego, which is extremely strong as it is fickle; its main aim is to "represent us" in the world as whatever we wish to pose to be. It ensures that the Id does not come out of us in over-stimulating situations. Hence, the ego, which is the only conscious part that is left, is formed right in the middle. This idea is used in modern Psychology to address the needs of mental patients. Granted, Freud's is NOT the only nor the most powerful analytical theory, but it opened the doors to the study of the unconscious; of what our brains are capable of doing and thinking, and creating, and hallucinating. Hence, the application of this theory, while it is mainly for psychological purposes, serves as a framework for other studies.
Erik Erikson, who was also a Freudian, is used in both the psychology, social, and educational fields. His proposed Psychosocial stages of development are similar to Piaget's in that they grant that there is a process in place for our brain to develop cognitively. However, he also places weight on the social factor, and the support systems that should be in place to strengthen our brain activity. Erik argues that each stage of life (by age), comes with a challenge. The challenge will result in a gain or a loss. The gain is the removal of an obstacle that would help us get to the next stage in a healthy way. The loss is the opposite: that the obstacle will become a hindrance that will make us stagnant. In this theory there are 8 stages:
- Trust vs. Mistrust = Good outcome - Hope
- Autonomy vs. Shame, Doubt = Good outcome- Willpower
- Initiative vs. Guilt- Good outcome= Purpose
- Industry vs. Inferiority= Competence
- Identify vs. Role Confusion= Fidelity
- Generativity vs. Stagnation= Care
- Integrity vs. Despair
Notice that these stages of development can be applied to the study of gerontology and needs of senior citizens, especially their psychology when they reach a stage where they are alone. Erikson is widely used as a checklist of sorts to understand behaviors per age.
Kohlberg's moral development is another cognitive theory based on how morality (our view of what is right vs. wrong) develops. It is also by stages, Preconventional (Rewards and Punishments handed out to us by adults), Convventional (Follow rules of friends, society at large), and Post Conventional (our own ethical principles). Kohlberg is used to study decision making patterns in people: double standards, why is one thing good for one thing but not another, choice making. It is also a foundation in psychology and one who holds its weight because it goes hand in hand with our maturity levels. Therefore all four of these theoretical concepts are vital to learn cognitive development.