and mouth the ball instead, accommodating or changing her schema to interact with the new object.
The processes of assimilation and accommodation enable people to adapt to their environment, absorbing the constant flux of information they encounter daily (see Figure 5.1). People—infants, children, and adults—constantly integrate new information into their schemas and continually encounter new information that requires them to modify their schemas. Piaget proposed that people naturally strive for cognitive equilibrium, a balance between the processes of assimilation and accommodation. When assimilation and accommodation are balanced, individuals are neither incorporating new information into their schemas nor changing their schemas in light of new information; instead, our schemas match the outside world and represent it clearly. But a state of cognitive equilibrium is rare and fleeting. More frequently, people experience a mismatch, or cognitive disequilibrium, between their schemas and the world.
Disequilibrium leads to cognitive growth because of the mismatch between schemas and reality. This mismatch leads to confusion and discomfort, which in turn motivate children to modify their cognitive schemas so that their view of the world matches reality. It is through assimilation and accommodation that this modification takes place so that cognitive equilibrium is restored. Children’s drive for cognitive equilibrium is the basis for cognitive change, propelling them through the four stages of cognitive development proposed by Piaget (refer to Chapter 1). With each advancing stage, children create and use more sophisticated cognitive schemas, enabling them to think, reason, and understand their world in more complex ways.
Figure 5.1 Assimilation and Accommodation
Bobby sees a cat that fits his schema for kitty (left). He has never seen a cat like this before (middle). He must accommodate his schema for kitty to include a hairless cat (right).
iStock/GlobalP; iStock/YouraPechkin
Sensorimotor Substages
“There you go, little guy,” Mateo’s uncle says, placing a rattle within the infant’s grasp. Six-month-old Mateo shakes the toy and puts it in his mouth, sucking on it. He then removes the rattle from his mouth and gives it a vigorous shake, dropping it to the ground. “Mateo! Where’s your rattle?” asks his mother. “Whenever he drops his toy, he never looks for it,” she explains to Nico’s uncle, “Not even when it’s his favorite toy.” Mateo displays sensorimotor thinking. During the sensorimotor stage, from birth to about 2 years old, infants learn about the world through their senses and motor skills. To think about an object, they must act on it by viewing it, listening to it, touching it, smelling it, and tasting it. Piaget (1952) believed that infants are not capable of mental representation—thinking about an object using mental pictures. They also lack the ability to remember and think about objects and events when they are not present. Instead, in order to think about an object, an infant must experience it through both the visual and tactile senses. The sensorimotor period of reasoning, as Piaget conceived of it, progresses through six substages in which cognition develops from reflexes to intentional action to symbolic representation. At each stage infants are driven to learn and explore the world.
Substage 1: Reflexes (Birth to 1 Month)
In the first substage, newborns use their reflexes, such as the sucking and palmar grasp reflexes, to react to stimuli. During the first month of life, infants use these reflexes to learn about their world, through the process of assimilation; they apply their sucking schema to assimilate information and learn about their environment. At about 1 month of age, newborns begin to accommodate, or modify, their sucking behaviors to specific objects, sucking differently in response to a bottle versus a pacifier. For example, they may modify their sucking schema when they encounter a pacifier, perhaps sucking less vigorously and without swallowing. During the first month of life, newborns strengthen and modify their original reflexive schemas to explore the world around them.
In the first substage (birth to 1 month), newborns use their reflexes, such as the grasping reflex, to respond to stimuli, such as to grasp an adult’s finger.
©iStockphoto.com/damircudic
Substage 2: Primary Circular Reactions (1 to 4 Months)
During the second substage, infants begin to make accidental discoveries. Early cognitive growth in the sensorimotor period comes through engaging in circular reactions, the repetition of an action and its response. Infants learn to repeat pleasurable or interesting events that originally occurred by chance. Between 1 and 4 months, infants engage in behaviors called primary circular reactions, which consist of repeating actions involving parts of the body that produce pleasurable or interesting results. A primary circular reaction begins by chance, as the infant produces a pleasurable sensation and learns to repeat the behavior to make the event happen again and experience the pleasurable effect again. For example, an infant flails her arms and accidentally puts her hand in her mouth. She is surprised at the outcome (her hand in her mouth) and tries to make it happen again. Therefore, the infant repeats the behavior to experience and explore her body.
In the second substage (1 to 4 months), infants discover that they can control their bodies and repeat the behavior to experience and explore their bodies. This infant enjoys repeatedly grasping her feet.
©iStockphoto.com/NickyLloyd
Substage 3: Secondary Circular Reactions (4 to 8 Months)
During the third sensorimotor substage, as infants’ awareness extends further, they engage in secondary circular reactions, repetitions of actions that trigger responses in the external environment. Now the patterns of repetition are oriented toward making interesting events occur in the infant’s environment. For example, the infant shakes a rattle to hear its noise or kicks his legs to move a mobile hanging over the crib. Secondary circular reactions indicate that infants’ attention has expanded to include the environment outside their bodies and that they are beginning to understand that their actions cause results in the external world. In this way, infants discover new ways of interacting with their environments to continue experiencing sensations and events that they find pleasing.
During the fourth substage (8 to 12 months), infants demonstrate object permanence, the understanding that objects exist outside of sensory awareness.
Doug Goodman/Science Source
Substage 4: Coordination of Secondary Circular Reactions (8 to 12 Months)
Unlike primary and secondary circular reactions, behaviors that are discovered by accident, the coordination of secondary circular reactions substage represents true means–end behavior and signifies the beginning of intentional behavior. During this substage, infants purposefully coordinate two secondary circular reactions and apply them in new situations to achieve a goal. For example, Piaget described how his son, Laurent, combined the two activities of knocking a barrier out of his way and grasping an object. When Piaget put a pillow in front of a matchbox that Laurent desired, the boy pushed the pillow aside and grabbed the box. In this way, Laurent integrated two secondary circular reactions to achieve a goal. Now planning and goal-directed behavior