Horizontal and vertical décalage are terms coined by developmental psychologist Jean Piaget, which he used to describe the four stages in Piaget's theory of cognitive development: sensorimotor, preoperational, concrete operations, and formal operations. According to Piaget, horizontal and vertical décalage generally occur during the concrete operations stage of development. Horizontal décalage refers to fact that once a child learns a certain function, he or she does not have the capability to immediately apply the learned function to all problems. In other words, "a horizontal décalage arises when a cognitive structure that can be successfully applied to task X cannot, though it is composed of the same organization of logical operations, be extended to task Y." Horizontal décalage is frequently used in reference to a child's ability to solve different conservation tasks. This concept recognizes that an individual child will not necessarily be on the same level of functioning in all possible areas of performance. Rather, "concepts and schemas develop through operation on and manipulation of objects in a specific manner." Vertical décalage refers to a child using the same cognitive function in different stages across development. In this sense, a child is improving upon a certain cognitive function, such as seriation tasks, as he or she ages.
History The term 'décalage' was first used in psychology by Édouard Claparède, a Swiss neurologist and child psychologist, in 1917 in reference to consciousness. Long before Piaget coined the term, his studies in 1921 brought to light the idea that some tasks are more demanding for children than others based on their complexity. This information supports the information processing theory, an opposing theory of cognitive development. Piaget then used the term himself in 1941, as he was developing his theory of the cognitive development. In his research, Piaget discovered that while physical qualities (once developed) were invariant, children's problem solving abilities are not. His studies revealed certain "décalages," or shifts and inconsistencies, in a child's cognitive development.
Common examples An example of horizontal décalage is the invariance of quantity, which is typically mastered around the age of 6 or 7 when matter is concerned, at the age of 9 or 10 when weight is concerned, and around 11 or 12 years old when the invariant is volume. A 7-year-old child understands that when one of two equivalent balls of clay is transformed into a sausage-shape, the two lumps still consist of equal amounts of clay. The child, however, fails to correctly comprehend that the differently shaped clumps of clay weigh the same. Both tasks are similar, but the child is clearly unable to apply his understanding about the first situation to the second situation. A comparable phenomenon can be seen in a child's increasing ability to perform seriation tasks, which consists of ordering objects according to increasing or decreasing size. The ability to arrange rods in order of decreasing/increasing size is always acquired prior to the capacity to seriate according to weight. A commonly cited example of vertical décalage "can be observed between the constitution of practical or sensorimotor space and that of representative space " For example, at the age of 2, a child can navigate around a familiar environment, such as their home. It is not until years later that they can represent this knowledge symbolically by drawing a map. There is vertical décalage between a problem that a child can physically master and their ability to solve it in an abstract manner.
Neurobiological perspective Some psychologists take a neural network model approach to the idea of horizontal and vertical décalage. According to these psychologists, horizontal and vertical décalage are the product of the development of the prefrontal cortex in children, which "contributes to age-related advances in flexible behavior". Certain tests and studies have been conducted to show how horizontal and vertical décalage are related to neural functioning. For example, scientists presented children with two identical balls of clay and then rolled one into a cylinder, changing its shape. When scientists then asked children which clump of clay contained more clay (conservation of mass), children were able to answer correctly that both clumps had equal amounts of clay. Children of the same age, however, were unable to answer which clump of clay weighed more (conservation of weight). This is an example of horizontal décalage because children were able to solve certain conservation tasks but not others despite their similarities. According to the neural network approach, as a child's prefrontal cortex develops, he or she is better able to maintain their knowledge "rules" and apply problem solving techniques across different situations. The development of the prefrontal cortex comes from the strengthening of neural synapses, a process which is remarkably heightened in childhood.
… excerpt ends here. Continue reading the full article.
