Cognitive development

The first stage in Piaget's stages of cognitive development is the sensorimotor stage. This stage lasts from birth to two years old. During this stage, behaviors lack a sense of thought and logic. Behaviors gradually move from acting upon inherited reflexes to interacting with the environment with a goal in mind and being able to represent the external world at the end.

The sensorimotor stage has been broken down into six sub-stages that explain the gradual development of infants from birth to age 2. Once the child gains the ability to mentally represent reality, the child begins the transition to the preoperational stage of development.[19]

Each child is born with inherited reflexes that they use to gain knowledge and understanding about their environment. Examples of these reflexes include grasping and sucking.[20]

From 1 to 4 months of age, children repeat behaviors that happen unexpectedly because of their reflexes. For example, a child's finger comes in contact with the mouth and the child starts sucking on it. If the sensation is pleasurable to the child, then the child will attempt to recreate the behavior.[20] Infants use their initial reflexes (grasping and sucking) to explore their environment and create schemas. Schemas are groups of similar actions or thoughts that are used repeatedly in response to the environment.[21] Once a child begins to create schemas they use accommodation and assimilation to become progressively adapted to the world.[22] Assimilation is when a child responds to a new event in a way that is consistent with an existing schema. For example, an infant may assimilate a new teddy bear into their putting things in their mouth scheme and use their reflexes to make the teddy bear go into their mouth.[21] Accommodation is when a child either modifies an existing schema or forms an entirely new schema to deal with a new object or event. For example, an infant may have to open his or her mouth wider than usual to accommodate the teddy bear's paw.[21]

Between 5 and 8 months of age, the child has an experience with an external stimulus that they find pleasurable, so they try to recreate that experience. For example, a child accidentally hits the mobile above the crib and likes to watch it spin. When it stops the child begins to grab at the object to make it spin again. In this stage, habits are formed from general schemas that the infant has created but there is not yet, from the child's point of view, any differentiation between means and ends.[23] Children cannot also focus on multiple tasks at once, and only focus on the task at hand.[21] The child may create a habit of spinning the mobile in its crib, but they are still trying to find out methods to reach the mobile in order to get it to spin in the way that they find pleasurable. Once there is another distraction (say the parent walks in the room) the baby will no longer focus on the mobile. Toys should be given to infants that respond to a child's actions to help foster their investigative instincts.[24] For example, a toy plays a song when you push one button, and then a picture pops up if you push another button.

From 8 to 12 months old, behaviors will be displayed for a reason rather than by chance. They begin to understand that one action can cause a reaction.[20] They also begin to understand object permanence, which is the realization that objects continue to exist when removed from view. For example: The baby wants a rattle but the blanket is in the way. The baby moves the blanket to get the rattle. Now that the infant can understand that the object still exists, they can differentiate between the object, and the experience of the object. According to psychologist David Elkind, "An internal representation of the absent object is the earliest manifestation of the symbolic function which develops gradually during the second year of life whose activities dominate the next stage of mental growth."[25]

From 12 to 18 months old, actions occur deliberately with some variation. For example, a baby drums on a pot with a wooden spoon, then drums on the floor, then on the table.[20]

Between 18 and 24 months of age, children begin to build mental symbols and start to participate in pretend play. For example, a child is mixing ingredients together but does not have a spoon so they pretend to use one or use another object to replace the spoon.[20] Symbolic thought is a representation of objects and events as mental entities or symbols which helps foster cognitive development and the formation of imagination.[26] According to Piaget, the infant begins to act upon intelligence rather than habit at this point. The end product is established after the infant has pursued for the appropriate means. The means are formed from the schemas that are known by the child.[23] The child is starting to learn how to use what it has learned in the first two years to develop and further explore their environment.

The preoperational stage lasts from 2 years of age until 6 or 7. It can be characterized in two somewhat different ways. In his early work, before he had developed his structuralist theory of cognition, Piaget described the child's thoughts during this period as being governed by principles such as egocentrism, animism, and other similar constructs. Egocentrism is when a child can only see a certain situation his or her own way. One cannot comprehend that other people have other views and perceptions of scenarios. Animism is when an individual gives a lifeless object human-like qualities. An individual usually believes that this object has human emotions, thoughts, and intentions. Once he had proposed his structuralist theory, Piaget characterized the preoperational child as lacking the cognitive structures possessed by the concrete operational child. The absence of these structures explains, in part, the behaviors Piaget had previously described as egocentric and animistic, for example, an inability to comprehend that another individual may have different emotional responses to similar experiences.[19][27] During this stage children also become increasingly adept at using symbols as evidenced by the increase in playing and pretending.

Lasts from 6 or 7 years until about 12 or 13. During this stage, the child's cognitive structures can be characterized by reality. Piaget argues that the same general principles can be discerned in a wide range of behaviors. One of the best-known achievements of this stage is conservation. In a typical conservation experiment a child is asked to judge whether or not two quantities are the same – such as two equal quantities of liquid in a short and tall glass. A preoperational child will typically judge the taller, thinner glass to contain more, while a concrete operational child will judge the amounts still to be the same. The ability to reason in this way reflects the development of a principle of conservation.[19]

This stage lasts from 12 or 13 until adulthood, when people are advancing from logical reasoning with concrete examples to abstract examples. The need for concrete examples is no longer necessary because abstract thinking can be used instead. In this stage adolescents are also able to view themselves in the future and can picture the ideal life they would like to pursue. Some theorists believe the formal operational stage can be divided into two sub-categories: early formal operational and late formal operation thought. Early formal operational thoughts may be just fantasies, but as adolescents advance to late formal operational thought the life experiences they have encountered changes those fantasy thoughts to realistic thoughts.[19]

Many of Piaget's claims have fallen out of favor. For example, he claimed that young children cannot conserve numbers. However, further experiments showed that children did not really understand what was being asked of them. When the experiment is done with candies, and the children are asked which set they want rather than having to tell an adult which is more, they show no confusion about which group has more items. Piaget argues that the child cannot conserve numbers if they do not understand one-to-one correspondence.[28]

Piaget's theory of cognitive development ends at the formal operational stage that is usually developed in early adulthood. It does not take into account later stages of adult cognitive development as described by, for example, Harvard University professor Robert Kegan.[29]

Additionally, Piaget largely ignores the effects of social and cultural upbringing on stages of development because he only examined children from western societies. This matters as certain societies and cultures have different early childhood experiences. For example, individuals in nomadic tribes struggle with number counting and object counting. Certain cultures have specific activities and events that are common at a younger age which can affect aspects such as object permeance. This indicates that children from different societies may achieve a stage like the formal operational stage while in other societies, children at the exact same age remain in the concrete operational stage.[30]

While working as a student of Edward Sapir, Benjamin Lee Whorf posited that a person's thinking depends on the structure and content of their social group's language. Per Whorf, language determines our thoughts and perceptions.[37] For example, it used to be thought that the Greeks, who wrote left to right, thought differently than Egyptians since the Egyptians wrote right to left. Whorf's theory was so strict that he believed if a word is absent in a language, then the individual is unaware of the object's existence.[38] This theory was played out in George Orwell's book, Animal Farm; the pig leaders slowly eliminated words from the citizen's vocabulary so that they were incapable of realizing what they were missing.[39] The Whorfian hypothesis failed to recognize that people can still be aware of the concept or item, even though they lack efficient coding to quickly identify the target information.[38]

Willard Van Orman Quine argued that there are innate conceptual biases that enable the acquisition of language, concepts, and beliefs.[40] Quine's theory follows nativist philosophical traditions, such as the European rationalist philosophers, for example Immanuel Kant.

Neo-Piagetian theories of cognitive development emphasized the role of information processing mechanisms in cognitive development, such as attention control and working memory. They suggested that progression along Piagetian stages or other levels of cognitive development is a function of strengthening of control mechanisms and is within the stages themselves. [41]

From cultural psychologists' view, minds and culture shape each other. In other words, culture can influence brain structures which then influence our interpretation of the culture. These examples reveal cultural variations in neural responses:

Behavioral research has shown that one's strength in independent (tasks which are focused on influencing others or oneself) or interdependent tasks (tasks where one changes their own behavior to favor others) differ based on their cultural context. In general, East Asian cultures are more interdependent whereas Western cultures are more independent. Hedden et al. assessed functional magnetic resonance imaging (fMRI) responses of East Asians and Americans while they performed independent (absolute) or interdependent (relative) tasks. The study showed that participants used regions of the brain associated with attentional control when they had to perform culturally incongruent tasks. In other words, neural paths used for the same task were different for Americans and East Asians.[43]

New studies in transcultural neuroimaging studies have demonstrated that one’s cultural background can influence the neural activity that underlies both high (for example, social cognition) and low (for example, perception) level cognitive functions. Studies demonstrated that groups that come from different cultures or that have been exposed to culturally different stimuli have differences in neural activity. For example, differences were found in that of the pre motor cortex during mental calculation and that of the VMPFC during trait judgements of one’s mother from people with different cultural backgrounds. In conclusion, since differences were found in both high-level and low-level cognition one can assume that our brain’s activity is strongly and, at least in part, constitutionally shaped by its sociocultural context.[44]

Kobayashi et al. compared American-English monolingual and Japanese-English bilingual children's brain responses in understanding others' intentions through false-belief story and cartoon tasks. They found universal activation of the region bilateral ventromedial prefrontal cortex in theory of mind tasks. However, American children showed greater activity in the left inferior frontal gyrus during the tasks whereas Japanese children had greater activity in the right inferior frontal gyrus during the Japanese Theory of Mind tasks. In conclusion, these examples suggest that the brain's neural activities are not universal but are culture dependent.[45]

Being deaf or hard-of-hearing has been noted to impact cognitive development as hearing loss impacts social development, language acquisition, and the culture reacts to a deaf child.[46] Cognitive development in academic achievement, reading development, language development, performance on standardized measures of intelligence, visual-spatial and memory skills, development of conceptual skills, and neuropsychological function are dependent upon the child's primary language of communication, either American Sign Language or English, as well as if the child is able to communicate and use the communication modality as a language.[47] There is some research pointing to deficits in development of theory of mind in children who are deaf and hard-of-hearing which may be due to a lack of early conversational experience.[48] Other research points to lower scores on the Wechsler Intelligence Scale for Children,[49] especially in the Verbal Comprehension Index[50] due differences in cultural knowledge acquisition.[51]

Since the 2010s there has been an increase in research into how transgender people fit into cognitive development theory.[52] At the earliest, transgender children can begin to socially transition during identity exploration. In 2015, Kristina Olson and colleagues studied transgender youth in comparison to their cisgender siblings and unrelated cisgender children. The students participated in the IAT, a test that measures how one may identify based on a series of questions related to memory. Overall it determines a child's gender preference. It showed that the transgender children's results correlated with their desired gender. The behaviors of the children also related back to their results. For instance, the transgender boys enjoyed food and activities typically associated and enjoyed by cisgender boys. The article reports that the researchers found that the children were not confused, deceptive, or oppositional of their gender identity, and responded with actions that are typically represented by their gender identity.[53]