Piaget’s Theory of Cognitive Development 1 The Prefrontal Cortex This portion of the brain (bright blue) shows extensive development from 3 to 6 years of age and is believed to play important roles in attention and working memory Prefrontal cortex 2 Figure 8.1 7.2 Piaget’s Four Stages of Cognitive Development The Sensorimotor Stage The Preoperational Stage The Concrete Operational Stage The Formal Operational Stage 3 Piaget’s Piaget’sStages Stagesof ofCognitive Cognitive Development Development Formal Operations (adolescence to adult) Concrete Operations (~ 7-12 yrs) Preoperational Period (~2 to 6 yrs) Sensorimotor Period Inborn Reflexes (~Birth to 2 yrs) 4 CONCRETE OPERATIONAL STAGE FORMAL OPERATIONAL STAGE The child begins to represent the world with words and images. These words and images reflect increased symbolic thinking and go beyond the connection of sensory information and physical action. He child can now reason logically about concrete events and classify objects into different sets The adolescent reasons in more abstract, idealistic, and logical ways. 2 to 7 Years of Age 7 to 11 Years of Age 11 Years of Ages Through Adulthood SENSORIMOTOR STAGE PREOPERATIONAL STAGE The infant constructs an understanding of the world by coordinating sensory experiences with physical actions. And infant progresses from reflexive, instinctual action at birth to the beginning of symbolic thought toward the end of the stage Birth to 2 Years of Age 5 7.2 The Sensorimotor Stage • From birth to approximately 2 years • Begins with reflexive responding and ends with using symbols • Object permanence: understanding that objects exist independently 6 7.2 The Preoperational Stage • From approximately 2 to 7 years • Children use symbols but are many errors in thinking > Egocentrism: The inability to distinguish between one’s own perspective and someone else’s perspective. > Confuse appearance and reality 7 Three Mountains Problem 8 7.2: The Preoperational Stage The Three Mountain Tasks 9 Conservation Tasks 10 7.2: The Preoperational Stage Piaget’s Conservation Task 11 Piaget’s Conservation Task A B C Two identical beakers shown to child, and then experimenter pours liquid from (B) into (C) A B C Child is asked if (A) and (C) have the same amount of liquid. The preoperational child says “no” and will point to (C) as having more liquid than (A). 12 Figure 8.8 Some Dimensions of Conservation: Number, Matter, and Length Type of conservation Initial presentation Number Matter Length Two identical rows of objects shown to child Two identical balls of clay shown to child Two sticks are aligned in front of child One row is spaced Experimenter changes shape of one ball Experimenter moves one stick to right “No, the longer one has more” “No, the one on top is longer” Manipulation Preoperational child’s answer to “No, the longer row has more” “Are they still the same?” 13 Figure 8.9 7.2 The Concrete Operational Stage • From approximately 7 to 11 years • Thinking based on mental operations (strategies and rules that make thinking more systematic and powerful) • Operations can be reversed • Focus on the real and concrete, not the abstract 14 7.2 The Formal Operational Stage • From approximately 11 years to adulthood • Adolescents can think hypothetically • Use deductive reasoning 15 Object Permanence and the “Impossible Event” 16 7.3: Criticisms of the Theory Theory of Mind 17 7.4 The Child as Theorist The Sociocultural Perspective: Vygotsky’s Theory • Cognitive development is inseparable from social and cultural contexts • Zone of proximal development: difference between what can do alone or with assistance • Scaffolding: teaching style that matches assistance to learner’s needs The Zone of Proximal Development (ZPD) student can work with the student can work ZPD assistance of an instructor ________________________ independently 18 19 Comparison of Vygotsky’s and Piaget’s Theories Vygotsky Piaget Sociocultural Context • Strong emphasis • Little emphasis Constructivism Stages • Social constructivist • No general stages • Zone of proximal development, language, dialogue, tools of the culture • Cognitive constructivist • Strong emphasis on stages • Schemata, assimilation, accommodation, operations, conservation, classification, hypothetical-deductive reasoning •It has a major role in shaping thought •It has a central role •Teacher is facilitator and guide, not director •It has a minimal role Key processes Role of language View on education Implications for teacher •It just defines existing skills •Teacher is facilitator and guide, not director 20 Figure 8.11 Developmental Changes in Memory Span 8 7 In one study: memory span increased from 3 digits at age 2, to 5 digits at age 7, to 7 digits at age 12. 6 5 Digit Span 4 3 2 1 0 2 4 6 8 10 12 Adult Age (years) 21 Figure 8.13 Piaget’s Stages of Cognitive Development Sensorimotor Birth to 2 years Infants know the world through their senses and through their actions. For example, they learn what dogs look like and what petting them feels like. Preoperational 2-7 years Toddlers and young children acquire the ability to internally represent the world through language and mental imagery. They also begin to be able to see the world from other people’s perspectives, not just from their own. 22 Piaget’s Stages of Cognitive Development Concrete Operational 7 - 12 years Children become able to think logically, not just intuitively. They now can classify objects into coherent categories and understand that events are often influenced by multiple factors, not just one. Formal Operational 12+ years Adolescents can think systematically and reason about what might be as well as what is. This allows them to understand politics, ethics, and science fiction, as well as to engage in scientific reasoning. 23 Sensorimotor Substages Sub Age Description 1 Birth – 1 Infants begin to modify the month reflexes with which they are born to make them more adaptive. 2 1–4 months Infants begin to organize separate reflexes into larger behaviors, most of which are centered on their own bodies. 24 Sensorimotor Substages Sub Age Description 3 4–8 months Infants becoming increasingly interested in the world around them. By the end of this substage, object permanence, the knowledge that objects continue to exist even when they are out of view, typically emerges. 4 8 – 12 months During this substage, children make the A-Not-B error, the tendency to reach to where objects have been found before, rather than to where they were last hidden. 25 Object permanence Objects are tied to infant’s awareness of them – “out of sight, out of mind” Hidden toy experiment – 4 months: no attempt to search for hidden object – 4-9 months: visual search for object – 9 months: search for and retrieve hidden object A-not-B task (Diamond, 1985) – 9 months: A/B error after 1/2 second delay – 12 months: 10 second delay needed to produce error 26 Piaget’s A-Not-B Task 27 Sensorimotor Substages Sub Age Description 5 12 – 18 months Toddlers begin to actively and avidly explore the potential uses to which objects can be put. 6 18 – 24 months Infants become able to form enduring mental representations. The first sign of this capacity is deferred imitation, the repetition of other people’s behavior a substantial time after it occurred. 28 Preoperational Stage A mix of impressive cognitive acquisitions and equally impressive limitations – A notable acquisition is symbolic representation, the use of one object to stand for another, which makes a variety of new behaviors possible – A major limitation is egocentrism, the tendency to perceive the world solely from one’s own point of view – A related limitation is centration, the tendency to focus on a single, perceptually striking feature of an object or event – Preoperational children also lack of understanding of the conservation concept, the idea that merely changing the appearance of objects does not change their key properties 29 Piaget’s Three-Mountain Task 30 Egocentric Conversations 31 The Balance Scale: An Example of Centration 32 Procedures Used to Test Conservation 33 Concrete Operational Stage Children begin to reason logically about the world They can solve conservation problems, but their successful reasoning is largely limited to concrete situations Thinking systematically remains difficult 34 Inhelder and Piaget’s Pendulum Problem The task is to compare the motions of longer and shorter strings, with lighter and heavier weights attached, in order to determine the influence of weight, string length, and dropping point on the time it takes for the pendulum to swing back and forth Children below age 12 usually perform unsystematic experiments and draw incorrect conclusions 35 Formal Operational Stage Cognitive development culminates in the ability to think abstractly and to reason hypothetically Individuals can imagine alternative worlds and reason systematically about all possible outcomes of a situation Piaget believed that the attainment of the formal operations stage, in contrast to the other stages, is not universal 36 Implications for Education Piaget’s view of children’s cognitive development suggests that children’s distinctive ways of thinking at different ages need to be considered in deciding how best to teach them In addition, because children learn by mentally and physically interacting with the environment, relevant physical activities, accompanied by questions that call attention to the lessons of the activities, are important in educational practice 37 Critique of Piaget’s Theory Although Piaget’s theory remains highly influential, some weaknesses are now apparent – The stage model depicts children’s thinking as being more consistent than it is – Infants and young children are more cognitively competent than Piaget recognized Object permanence in 3-month-olds (Bower, 1974) Number conservation in 4 year olds (McGarrigle & Donaldson, 1974) 38 Critique of Piaget’s Theory – Piaget’s theory understates the contribution of the social world to cognitive development Piaget’s tasks are culturally biased Schooling and literacy affect rates of development – e.g. Greenfield’s study of the Wolof Formal operational thinking is not universal – e.g. Gladwin’s study of the Polynesian islanders – Piaget’s theory is vague about the cognitive processes that give rise to children’s thinking and about the mechanisms that produce cognitive growth 39