Crash Course in Cognitive Development (well, one model anyway)
According to Piaget, an individual progresses through discrete stages, eventually developing the skills to perform scientific reasoning. After passing through the early stages of cognitive development as young children, individuals reach the penultimate stage, known as concrete operational, at which point they are able to classify objects and understand conservation, but are not yet able to form hypotheses or understand abstract concepts.
In the final stage, known as formal operational, an individual has the ability to think abstractly. At this point, an individual is able to control and isolate variables, search for relationships, such as proportions, understand probability, and lastly, formulate hypotheses and test them with carefully designed experiments.
To progress, individuals must actively reconcile new information with their existing knowledge.
Contrary to Piaget’s theoretical notion that most teenagers reach the formal stage, educational researchers have shown that many high school students, as well as college students, have not reached that stage. Arons and Karplus claim that only one-third of college students are formal operational thinkers. 1