Stages of Cognitive Development: An Overview
We’ll start with the obvious: a kindergartener is not the same as a 6th-grade student is not the same as a 12th-grade student. The differences are too numerous to list. Over 50 years ago Piaget proposed categorizing these differences into four stages of development, distributed into ages 0-2, 2-7, 7-12 and 12 onwards. Based on these stages a teacher should be able to predict how each student will respond to certain material, what will be too abstract or otherwise require abilities that are not yet developed. Similar theories have been proposed by Freud, Erikson, Kohlberg, Loevinger, and others.
Some modern versions of developmental stage theories are based in neuroscience, invoking what are called “critical periods” or “sensitive periods.” The claim is that during sensitive periods, the brain requires certain stimuli to develop properly. Oft cited in this literature is the fact that adults, blinded by cataracts for 5 years, can see once the cataracts are removed. But children born with cataracts, if operated on at age 5 years, remain blind. With the cataracts removed, the eyes are able to receive input and transmit signals to the brain, but the brain never learned—and no longer can learn—to translate those signals into images. This observation is extended to posit many such sensitive periods, especially during the first three years of life.
The Five Claims
There is no question that people have different learning capabilities at different ages. Rather, the question is how much of this difference is simply due to prior knowledge and experience versus being due to sensitive periods or stages of cognitive development? The following are five common claims regarding developmental stages and sensitive periods followed by their status according to current research:
- Distinct developmental stages exist that all children pass through at more or less the same time and order. Status: FALSE
- Distinct developmental stages exist that enable or inhibit performance on certain types of tasks. Status: FALSE
- Teaching content that is not aligned with a particular stage of development or sensitive period is ineffectual. Status: FALSE
- There are sensitive periods specific to academic disciplines—e.g., art, music, drama, history, reading or language arts, mathematics, and science—that should influence curriculum and pedagogy. Status: FALSE
- There are sensitive periods specific to language development that should influence L1 and L2 curriculum and pedagogy. Status: TRUE
Most human learning is not impacted by critical periods or on lessons being taught at a particular age. Unlike the development of vision, most things can be taught to children beyond their early years without detriment. There appears to be no particular benefit, for instance, to teaching music or number sense or reading to toddlers, despite claims to the contrary. Children learn these things at greatly varying ages and sequences in different countries, and their proficiency in upper grades bears little correlation to their start time in early childhood. When it comes to language, however, children deprived of verbal stimulation during their first few years do have greater difficulty acquiring normal language later on. Additionally, evidence suggests that some elements—specifically, grammar structures and phonetics—are more easily acquired before puberty, while other aspects of language development such as vocabulary and semantics are learned with equal ease across ages.
Given appropriate learning opportunities, children can acquire abilities prior to prescribed stages of cognitive development.1
According to the theory of developmental stages, children aged 4-6 should be unable to understand reversibility, which is that something can be changed back to its original state after it has been altered. For example, understanding that water poured back and forth between two differently shaped containers remains the same amount despite differences in height. To test whether reversibility could be taught to children ages 4-6, a computer-based educational game was developed that required reversible thinking to be successful. Children were given pre-tests, played the game for 30 minutes, and then given post-tests. Outcome: All children showed significant gains in their game play and reversible thinking as measured by a post-test. The gains were sustained in a follow-up test administered two weeks later.
Abilities depend largely on specific contexts and unknown differences. They cannot be divided into a consistent progression through stages according to age.2
One of Piaget’s central claims is that before a certain stage young children are unable to identify that another’s thoughts and perceptions are different from their own.
First study: A group of 18-month olds is given broccoli and crackers (almost all prefer crackers). Then, the researcher eats either the broccoli or the crackers and exclaims how incredibly tasty it is. The researcher then places her hand equidistant from the two bowls and asks the child to give her a snack. Outcome: About 90% of children offer the researcher the one that she exclaimed liking the most, regardless of which one they themselves liked.
Second study: Children aged 37 months to 46 months were shown a series of boxes that contained objects other than that indicated by their appearance (e.g. an egg box containing a spoon or a biscuit box with an orange). The children were asked what they thought was inside, shown what was actually inside, and then asked what a toy puppet who had been “sleeping” would think was inside. Students were tested once every four weeks for a total of six tests. Outcome: Nearly half of the children inconsistently answered with a correct understanding of the puppet’s perception.
Over time, substantial inconsistency in the same child’s abilities exists, suggesting that there is not a clear stage of development to which a child belongs.3
Children aged 54 to 73 months old were shown two rows of buttons. Each row had the same number of buttons and they are aligned, one for one. The children agreed that the rows are the same. Then the experimenter changed one row by pushing the buttons closer or farther apart. Then, the experimenter asked, which row has more? According to Piaget, younger children would solve the problem by going through specific stages of thinking in a particular order. Performing variants of the problem a total of 96 times over eight sessions, children were asked which row had more buttons and to explain why. Outcome: Children did not proceed through stages in order, but rather replied in a seemingly random fashion, sometimes getting the answer right with sophisticated reasoning, and then getting the next problem wrong with naïve reasoning.
While students at different ages do differ, no evidence exists that different ages correspond to distinct developmental stages. Rather, a student’s development proceeds along a much more complicated path, often in fits and starts and with substantial contextual influence. Similarly, with the exception of language, particular stimuli are generally not required at certain ages for normal cognitive development, nor are there age restrictions on when certain disciplines can be learned. More important than a student’s age is his or her prior knowledge, abilities, and interests, these things–not a hypothesized developmental stage–should form the basis of differentiated instruction.
“Top 20 Principles From Psychology for PreK–12 Teaching and Learning”, by the American Psychological Association, Coalition for Psychology in Schools and Education, 2015.
“What is Developmentally Appropriate Practice?” by Daniel Willingham, American Educator, 2008, 32(2), 34-39.
The Myth of the First Three Years: A New Understanding of Early Brain Development and Lifelong Learning by John Bruer, Free Press, 2002.
“The Persistence of Myth in Teacher Education and Training” by Catherine Cornbleth, 88-108, in Teacher Education: Curriculum and Change edited by David Hartley and Maurice Whitehead, Routledge, 2006.
“Critical Period Effects in Second Language Learning: The Influence of Maturational State on the Acquisition of English as a Second Language” by Jacqueline Johnson, and Elissa Newport, Cognitive Psychology, 1989, 21(1), 60-99.
- “Technology and Conservation: Facilitating Reversibility in Pre-Operational Subjects” by David Palumbo, William Lidwell, and Debra Lenamond, Presentation at the Annual Meeting of The Association for the Development of Computer-based Instructional Systems, 1991.
- “A Longitudinal, Microgenetic Study of the Emergence of False Belief Understanding and Inhibition Skills” by Emma Flynn, Claire O’Malley, and David Wood, Developmental Science, 2004, 7(1), 103-115.
- “How Does Change Occur: A Microgenetic Study of Number Conservation” by Robert Siegler, Cognitive Psychology, 1995, 28(3), 225-273.