Somewhere on your precarious journey "from egghood to personhood" (Broks, 2007), you became conscious. When was that, and how did your mind unfold from there? Developmental psychologist Jean Piaget [pee-ah-ZHAY] spent his life searching for the answers to such questions. He studied children's cognitive development-all the mental activities associated with thinking, knowing, remembering, and communicating. His interest began in 1920, when he was in Paris developing questions for children's intelligence tests. While administering the tests, Piaget became intrigued by children's wrong answers, which were often strikingly similar among same-age children. Where others saw childish mistakes, Piaget saw intelligence at work.
A half-century spent with children convinced Piaget that a child's mind is not a miniature model of an adult's. Thanks partly to his work, we now understand that children reason differently than adults, in "wildly illogical ways about problems whose solutions are selfevident to adults" (Brainerd,1996).
Piaget's studies led him to believe that a child's mind develops through a series of stages, in an upward march from the newborn's simple reflexes to the adult's abstract reasoning power. Thus, an 8-year-old can comprehend things a toddler cannot, such as the analogy that "getting an idea is like having a light turn on in your head," or that a miniature slide is too small for sliding, and a miniature car is much too small to get into (FIGURE 47.1).
Piaget's core idea is that the driving force behind our intellectual progression is an unceasing struggle to make sense of our experiences. To this end, the maturing brain builds schemas, concepts or mental molds into which we pour our experiences (FIGURE 47.2). By adulthood we have built countless schemas, ranging from cats and dogs to our concept of love.
To explain how we use and adjust our schemas, Piaget proposed two more concepts. have no schema for such an image. First, we assimilate new experiences-we interpret them in terms of our current understandings (schemas). Having a simple schema for dog, for example, a toddler may call all four-legged animals dogs. But as we interact with the world, we also adjust, or accommodate, our schemas to incorporate information provided by new experiences. Thus, the child soon learns that the original dog schema is too broad and accommodates by refining the category (FIGURE 47.3).
Piaget believed that children construct their understanding of the world while interacting with it. Their minds experience spurts of change, followed by greater stability as they move from one cognitive plateau to the next, each with distinctive characteristics that permit specific kinds of thinking. In Piaget's view, cognitive development consisted of four major stages - sensorimotor; preoperational, concrete operational, and formal operational.
In the sensorimotor stage, from birth to nearly age 2, babies take in the world through their senses and actions-through looking, hearing, touching, mouthing, and grasping. As their hands and limbs begin to move, they learn to make things happen.
Very young babies seem to live in the present: Out of sight is out of mind. In one test, Piaget showed an infant an appealing toy and then flopped his beret over it. Before the age of 6 months, the infant acted as if it ceased to exist. Young infants lack object permanence-the awareness that objects continue to exist when not perceived. By 8 months, infants begin exhibiting memory for things no longer seen. Ifyou hide a toy, the infant will momentarily look for it (FIGURE 47.4) . Within another month or two, the infant will look for it even after being restrained for several seconds.
So does object permanence in fact blossom at 8 months, much as tulips blossom in spring? Today's researchers think not. They believe object permanence unfolds gradually, and they see development as more continuous than Piaget did. Even young infants will at least momentarily look for a toy where they saw it hidden a second before (Wang et al., 2004).
Researchers also believe Piaget and his followers underestimated young children's competence. Consider these simple experiments:
Clearly, infants are smarter than Piaget appreciated. Even as babies, we had a lot on our minds.
Piaget believed that until about age 6 or 7, children are in a preoperational stage-too young to perform mental operations (such as imagining an action and mentally reversing it). For a 5-year-old, the milk that seems "too much" in a tall, narrow glass may become an acceptable amount if poured into a short, wide glass. Focusing only on the height dimension, this child cannot perform the operation of mentally pouring the milk back. Before about age 6, said Piaget, children lack the concept of conservation-the principle that quantity remains the same despite changes in shape (FIGURE 47.6).
Piaget did not view the stage transitions as abrupt. Even so, symbolic thinking (representing things with words and images) appears at an earlier age than he supposed. Judy DeLoache (1987) discovered this when she showed children a model of a room and hid a model toy in it (a miniature stuffed dog behind a miniature couch). The 21f2-year-olds easily remembered where to find the miniature toy, but they could not use the model to locate an actual stuffed dog behind a couch in a real room. Three-year-olds-only 6 months older-usually went right to the actual stuffed animal in the real room, showing they could think of the model as a symbol for the room. Piaget probably would have been surprised.
Piaget contended that preschool children are egocentric: They have difficulty perceiving things from another's point of view. Asked to "show Mommy your picture," 2-year-old Gabriella holds the picture up facing her own eyes. Three-year-old Gray makes himself "invisible" by putting his hands over his eyes, assuming that if he can't see his grandparents, they can't see him. Children's conversations also reveal their egocentrism, as one young boy demonstrated (Phillips, 1969, p. 61):
"Do you have a brother?"
"Yes."
"What's his name?"
“Jim."
"Does Jim have a brother?"
"No."
Like Gabriella, TV-watching preschoolers who block your view of the TV assume that you see what they see. They simply have not yet developed the ability to take another's viewpoint. Even teens and adults often overestimate the extent to which others share our opinions and perspectives, a trait known as the curse of knowledge. We assume that something will be clear to others if it is clear to us, or that text message recipients will "hear" our "just kidding" intent (Epley et al., 2004; Kruger et al., 2005). Children are even more susceptible to this tendency.
When Little Red Riding Hood realized her "grandmother" was really a wolf, she swiftly revised her ideas about the creature's intentions and raced away. Preschoolers, although still egocentric, develop this ability to infer others' mental states when they begin forming a theory of mind (a term first coined by psychologists to describe chimpanzees' seeming ability to read intentions [Premack & Woodruff, 1978]).
Infants as young as 7 months show some knowledge of others' beliefs (Kovacs et al., 2010). With time, the ability to take another's perspective develops. They come to understand what made a playmate angry, when a sibling will share, and what might make a parent buy a toy. And they begin to tease, empathize, and persuade. Between about 3 1/2 and 4 1/2, children worldwide come to realize that others may hold false beliefs (Callaghan et al., 2005; Sabbagh et al., 2006). Researchers showed Toronto children a Band-Aids box and asked them what was inside Qenkins & Astington, 1996). Expecting Band-Aids, the children were surprised to discover that the box actually contained pencils. Asked what a child who had never seen the box would think was inside, 3-year-olds typically answered "pencils." By age 4 to 5, the children's theory of mind had leapt forward, and they anticipated their friends' false belief that the box would hold Band-Aids.
In a follow-up experiment, children viewed a doll named Sally leaving her ball in a red cupboard (FIGURE 47.7). Another doll, Anne, then moves the ball to a blue cupboard. Researchers then pose a question: When Sally returns, where will she look for the ball? Children with autism spectrum disorder (ASD; see Close-up: Autism Spectrum Disorder and "Mind-Blindness") have difficulty understanding that Sally's state of mind differs from their own - that Sally, not knowing the ball has been moved, will return to the red cupboard. They also have difficulty reflecting on their own mental states. They are, for example, less likely to use the personal pronouns I and me. Deaf children with hearing parents and minimal communication opportunities have had similar difficulty inferring others' states of mind (Peterson & Siegal, 1999).
Diagnoses of autism spectrum disorder (ASO), a disorder marked by social deficiencies and repetitive behaviors, have been increasing, according to recent estimates. Once believed to affect 1 in 2500 children, ASD now affects 1 in 110 American children and about 1 in 100 in Britain (CDC, 2009; Lilienfeld & Arkowitz, 2007; NAS, 2011). The increase in ASD diagnoses has been offset by a decrease in the number of children considered "cognitively disabled" or "learning disabled," which suggests a relabeling of children's disorders (Gernsbacher et al., 2005; Grinker, 2007; Shattuck, 2006). A massive $6.7 billion National Children's Study now under way aims to enroll 100,000 pregnant women in 105 countries and to follow their babies until they turn 21 -partly in hopes of explaining the rising rates of ASD, as well as premature births, childhood obesity, and asthma (Bel luck, 2010; Murphy, 2008).
The underlying source of ASD's symptoms seems to be poor communication among brain regions that normally work together to let us take another's viewpoint. This effect appears to result from ASD-related genes interacting with the environment (State & Sestan, 2012). People with ASD are therefore said to have an impaired theory of mind (Rajendran & Mitchell, 2007; Senju et al., 2009). They have difficulty inferring others' thoughts and feelings. They do not appreciate that playmates and parents might view things differently. Mind reading that most of us find intuitive (Is that face conveying a smirk or a sneer?) is difficult for those with ASD. Most children learn that another child's pouting mouth signals sadness, and that twinkling eyes mean happiness or mischief. A child with ASD fails to understand these Signals (Frith & Frith, 2001). In hopes of a cure, desperate parents have sometimes subjected children to dubious therapies (Shute, 2010).
ASD (formerly referred to as "autism") has differing levels of severity. "High-functioning" individuals generally have normal intelligence, and they often have an exceptional skill or talent in a specific area. But they lack social and communication skills, and they tend to become distracted by minor and unimportant stimuli (Remington et al., 2009). Those at the spectrum's lower end are unable to use language at all.
ASD afflicts four boys for every girl. Psychologist Simon Baron-Cohen believes this hints at one way to understand this disorder. He has argued that ASD represents an "extreme male brain" (2008, 2009). Although there is some overlap between the sexes, he believes that boys are better "systemizers." They tend to understand things according to rules or laws, for example, as in mathematical and mechanical systems. Children exposed to high levels of the male sex hormone testosterone in the womb may develop more masculine and autistic traits (Auyeung et ai, 2009).
In contrast, girls are naturally predisposed to be "empathizers," Baron-Cohen contends. They are better at reading facial expressions and gestures, though less so if given testosterone (van Honk et al., 2011).
Biological factors, including genetic influences and abnormal brain development, contribute to ASD (State & Sestan, 2012). Childhood MMR vaccinations do not (Demicheli et al., 2012). Based on a fraudulent 1998 study-"the most damaging medical hoax of the last 100 years" (Flaherty, 2011) -some parents were misled into thinking that the childhood MMR vaccine increased risk of ASD. The unfortunate result was a drop in vaccination rates and an increase in cases of measles and mumps. Some unvaccinated children suffered long-term harm or even death.
Twin and sibling studies provide some evidence for biology's influence. If one identical twin is diagnosed with ASD, the chances are 50 to 70 percent that the co-twin will be as well (Lichtenstein et al., 2010; Sebat et al., 2007). A younger sibling of a child with ASD also is at a heightened risk (Sutcliffe, 2008). Random genetic mutations in sperm-producing cells may also playa role. As men age, these mutations become more frequent, which may help explain why an over-40 man has a much higher risk of fathering a child with ASD than does a man under 30 (Reichenberg et al., 2007). Researchers are now sleuthing ASD's telltale signs in the brain's synaptic and gray matter (Crawley, 2007; Ecker et al., 2010; Garber, 2007).
Biology's role in ASD also appears in brain-function studies. People without ASD often yawn after seeing others yawn. And as they view and imitate another's smiling or frowning , they feel something of what the other is feeling . Not so among those with ASD, who are less imitative and show much less activity in brain areas involved in mirroring others' actions (Dapretto et al., 2006; Perra et al., 2008; Senju et al., 2007). When people with ASD watch another person's hand movements, for example, their brain displays less than normal mirroring activity (Oberman & Ramachandran, 2007; Theoret et al., 2005). Scientists are continuing to explore and vigorously debate the idea that the brains of people with ASD have "broken mirrors" (Gallese et al., 2011).
Seeking to "systemize empathy," Baron-Cohen and his Cambridge University colleagues (2007; Golan et al ., 2010) collaborated with Britain's National Autistic Society and a film production company. Knowing that television shows with vehicles have been popular among kids with ASD, they created animations that grafted emotion-conveying faces onto toy tram , train, and tractor characters in a pretend boy's bedroom (FIGURE 47.8). After the boy leaves for school, the characters come to life and have experiences that lead them to display various emotions (which I predict you would enjoy viewing at www.thetransporters.com). The children were surprisingly able to generalize what they had learned to a new, real context. By the intervention's end, their previously deficient ability to recognize emotions on real faces now equaled that of children without ASD.
By age 6 or 7, said Piaget, children enter the concrete operational stage. Given concrete (physical) materials, they begin to grasp conservation. Understanding that change in form does not mean change in quantity, they can mentally pour milk back and forth between glasses of different shapes. They also enjoy jokes that use this new understanding:
Mr. Jones went into a restaurant and ordered a whole pizza for his dinner. When the waiter asked if he wanted it cut into 6 or 8 pieces, Mr. Jones said, "Oh, you'd better make it 6, I could never eat 8 pieces!" (McGhee, 1976)
Piaget believed that during the concrete operational stage, children become able to comprehend mathematical transformations and conservation. When my daughter, Laura, was 6, I was astonished at her inability to reverse simple arithmetic. Asked, "What is 8 plus 4?" she required 5 seconds to compute "12," and another 5 seconds to then compute 12 minus 4. By age 8, she could answer a reversed question instantly.
By age 12, our reasoning expands from the purely concrete (involving actual experience) to encompass abstract thinking (involving imagined realities and symbols) . As children approach adolescence, said Piaget, many become capable of thinking more like scientists. They can ponder hypothetical propositions and deduce consequences: If this, then that. Systematic reasoning, what Piaget called formal operational thinking, is now within their grasp.
Although full-blown logic and reasoning await adolescence, the rudiments of formal operational thinking begin earlier than Piaget realized. Consider this simple problem:
If John is in school, then Mary is in school. John is in school. What can you say about Mary?
Formal operational thinkers have no trouble answering correctly. But neither do most 7-year-olds (Suppes, 1982). TABLE 47.1 summarizes the four stages in Piaget's theory.
As Piaget was forming his theory of cognitive development, Russian psychologist Lev Vygotsky was also studying how children think and learn. He noted that by age 7, they increasingly think in words and use words to solve problems. They do this, he said, by internalizing their culture's language and relying on inner speech (Fernyhough, 2008). Parents who say "No, no!" when pulling a child's hand away from a cake are giving the child a self-control tool. When the child later needs to resist temptation, he may likewise say "No, no!" Second graders who muttered to themselves while doing math problems grasped third-grade math better the following year (Berk, 1994). Whether out loud or inaudibly, talking to themselves helps children control their behavior and emotions and master new skills.
Where Piaget emphasized how the child's mind grows through interaction with the physical environment, Vygotsky emphasized how the child's mind grows through
interaction with the social environment. If Piaget's child was a young scientist, Vygotsky's was a young apprentice. By mentoring children and giving them new words, parents and others provide a temporary scaffold from which children can step to higher levels of thinking (Renninger & Granott, 2005). Language, an important ingredient of social mentoring, provides the building blocks for thinking, notedVygotsky (who was born the same year as Piaget, but died prematurely of tuberculosis).
Effective mentoring occurs when children are developmentally ready to learn a new skill. For Vygotsky, a child's zone of proximal development was the zone between what a child can and can't do-it's what a child can do with help. When learning to ride a bike, it's the developmental zone in which a child can ride with training wheels or a steadying parental hand.
What remains of Piaget's ideas about the child's mind? Plenty-enough to merit his being singled out by Time magazine as one of the twentieth century's 20 most influential scientists and thinkers and rated in a survey of British psychologists as the last century's greatest psychologist (Psychologist, 2003). Piaget identified significant cognitive milestones and stimulated worldwide interest in how the mind develops. His emphasis was less on the ages at which children typically reach specific milestones than on their sequence. Studies around the globe, from aboriginal Australia to Algeria to North America, have confirmed that human cognition unfolds basically in the sequence Piaget described (Lourenco & Machado, 1996; Segall et al., 1990).
However, today’s researchers see development as more continuous than did Piaget. By detecting the beginnings of each type of thinking at earlier ages, they have revealed conceptual abilities Piaget missed. Moreover, they see formal logic as a smaller part of cognition than he did. Piaget would not be surprised that today, as part of our own cognitive development, we are adapting his ideas to accommodate new findings.
Future parents and teachers remember: Young children are incapable of adult logic. Preschoolers who block one's view of the TV simply have not learned to take another's viewpoint. What seems simple and obvious to us-pestering a cat will lead to scratches-may be incomprehensible to a 3-year-old. Also remember that children are not passive receptacles waiting to be filled with knowledge. Better to build on what they already know, engaging them in concrete demonstrations and stimulating them to think for themselves. And, finally, accept children's cognitive immaturity as adaptive. It is nature's strategy for keeping children close to protective adults and providing time for learning and socialization (Bjorklund & Green, 1992).
