9.1 Briefly describe the Piaget’s sensori-motor sub stages;
9.2 Provide examples of behaviours in Piaget’s sensori-motor sub stages.
PIAGET’S SENSORI- MOTOR SUBSTAGES
After outlining the processes that infants use to acquire knowledge, Piaget began to describe the differences in the ways infants, preschoolers, school-age children, and adolescents understand their environments. At each of these ages, different internal structures are operating. The internal organizations that infants exhibit are limited. Unlike adults, infants are not constantly thinking about their environment. Their knowledge is based on actions. These actions become organized into patterns of behaviours called schemes. For older children and adults, schemes are like concepts, but for these infants they are organisations of behaviours.
Cognitive growth is the result of the infant actively exploring the environment and developing more organized schemes. During the first two years, Piaget outlines six different milestones based on the child’s rapidly changing schemes.
Stage I: Exercising reflexes and built-in patterns of behaviour: (Birth to I month): The newborn’s beginning equipment, as we have seen, is primarily a set of reflexes and some loosely patterned behaviours. These reflexes and beginning sensory skills constitute the initial organization of the child. During the first month, through the dual processes of assimilation and accommodation, these initial skills become more stable, more useful, and more organized. After perfecting the sucking reflex, the infant may suck fingers, blankets, stuffed animals, and his parents’ shoulders. The same is true of the “looking” reflex. In the first week, the infant’s eyes are not always coordinated. By exercising the eyes, the pattern of behaviour that is called “looking” becomes well established. During active alert states, the infant does a great deal of looking. Even the grasping reflex changes during the first month of life and is gradually transformed into a grasping scheme. All of these initial behaviours—sucking, looking, and grasping—are part of the infant’s initial equipment. As these skills become more organized, they provide the infant with a way to explore. The looking scheme, the grasping scheme, and the sucking scheme are actually the organizations that guide the infant’s transactions with the environment. More sophisticated structures evolve from these rudimentary schemes.
Notice that there is very little intentional behaviour during this period. Infants do not decide to suck a pacifier. When a pacifier accidentally touches the lips, the infant begins sucking. The automatic character of the infant’s response is a hallmark of Stage 1.
Stage 2: Extending reflexes (I to 4 months): Before infants can really understand the world, they must coordinate the information that is being gathered through the schemes of looking, grasping, or sucking. Although this coordination takes time, the beginning steps are seen during the second stage of the sensory motor period. At the beginning of this stage, the infant notices the association between some action and a consequence. For example, Laurent’s hand somehow gets into his mouth. When he loses contact with his hand, he tries again to get his hand into his mouth. His arms, instead of gesticulating aimlessly, constantly move toward his mouth. Thirteen times in succession I have been able to observe the hand go back into the mouth. There is no longer any doubt that coordination exists. His right hand may be seen approaching his mouth. But as only the index finger was grasped, the hand fell out again. Shortly after, it returned. This time the thumb was in the mouth. I then remove the hand and place it near his waist. After a few minutes, the lips move and the hand approaches them again. (Piaget, 1952, p. 52—53)
The importance of the second stage of sensory motor development is that the schemes we saw in the first stage no longer exist in isolation. The infant begins to relate these behaviours. Laurent’s struggle to get his hand into his mouth illustrates the gradual changes that take place in the sucking ad grasping schemes so that ultimately infants can direct their hand to their mouth quickly and effectively. Laurent is practicing two schemes—sucking with his mouth and swiping with his hands. Initially, these two actions are isolated. As he achieves hand-mouth coordination, a new higher level behavioural scheme is established. Now he can manoeuvre his hands into his mouth. This new action reflects the infant’s revised organization or structure.
In addition to coordination, we see that the infant takes a more directive role in exploring. Looking is one scheme that demonstrates this increased control. When looking was merely an exercise, it was not particularly directed. Now Laurent explores by looking. This is a subtle change but an extremely important one. When reflexes were the primary way of responding, the infant had much less control. Now the infant is influencing the exploration, the looking, and the grasping. The simple act of looking at what you are holding requires that the child’s eyes and hands work together. The process of coordinating the schemes of grasping and looking involves the following states: (1) swipes at object, (2) unilateral hand raising, (3) both hands raised, (4) hand regard, (5) alternating glance between hand and object, and (6) clasping hands together.
In the second stage of the sensory motor period, there is a definite change from the reflexive behaviour of the first stage. The skills that the child had at birth have been practiced and organized into higher level schemes that involve two senses. More importantly, infants have much more control over these behaviours.
Stage 3: Integrating senses (4 to 10 months): Each stage builds on the one before, and comparing behaviours in two adjacent stages makes the limits of the earlier stage and the progress of the later stage clear. In this period, all the senses become fully coordinated. Not only can infants get their thumbs into their mouths, they can see or hear an object, direct their arm to it, grab it, and put it in their mouths. Jacqueline hears a rattle shake. She cannot see it, but she reaches in the direction of the sound and turns her head to see if she can see the rattle. When her hands touch it, she grabs it and pull it into view. She finishes this whole coordinated sequence by sucking on the object she obtains. The coordination of earlier, isolated schemes (i.e., seeing, grasping, sucking) is complete. The child now has a more flexible and more sophisticated organization to guide the exploration of the environment.
In this stage, the intentions and goals that were missing before become more evident. The child observes an action, then tries to reproduce it. For example, rhythmical kicking causes some toys attached to Jacqueline’s bassinet to shake. This display motivates her to try to make them shake again. The initial occurrence is, as in the second stage, accidental. But once it happens, the child can wilfully reproduce it.
The combination of fully coordinated schemes and the ability to carry out simple goals helps the child explore everyday objects. Toward the end of this stage, infants understand that objects exist independently of them. This realization, fittingly called the object concept, is really a monumental accomplishment because it signals the beginning of symbolic processes. To understand that an object is permanent and still exists when it cannot be seen or heard or felt means that the infant has developed some way to imagine or remember the object. Acquiring an object concept signifies a transition from relying on actions and simple schemes to representing the world in the mind. Hence, we need to examine the object concept in some detail To form an object concept, infants must first understand that an object is the sum of their impressions. Mother is no longer an isolated voice, a particular face, or a pleasant odour as she was in Stage 1. Now that these schemes are integrated, the child forms a multifaceted representation of mother. It takes many hours of contact with an object and a lot of active exploration to understand all of its facets. Infants have this kind of contact with their mothers. Hence, it is not surprising that the first object that infants seem to understand as a collection of different pieces of information is their mother.
At the University of Edinburgh, Bower devised a mirror illusion to show the change in the way infants perceived their mothers. Bower arranged mirrors so that several replicas of the mother appeared in the baby’s view. Before five months of age, the children were not upset by these multiple images. After about five months, seeing several images upset the infants. Bower (1982) concludes that having laboriously decided that they have only one mother, infants five months and older are disturbed by the appearance of several mothers.
Earlier we noted that infants could recognize their mother’s face, voice, and odour during the first month of life. In the first month, the mother’s face and voice were isolated because the schemes of looking and hearing were not coordinated. The essence of the infant’s task during the third stage of sensory motor development is to coordinate the senses. Hence, what was known before as a familiar voice now becomes linked with information about odours and face so that together these coordinated schemes define a new concept—mother. The object concept is first evident when infants realize that their mother exists independently of them. But the object concept continues to evolve during stage four and encompasses much more than the child’s parents.
Stage 4: Coordination of schemes: 10 to 12 months. During this stage, infants begin to understand other objects in the same way they under- stand their parents’ permanence. Prior to developing an object concept, an infant seems to think that any change in the object makes it a different object. Keith Moore has a compelling video tape of a six-month-old girl reaching for a Kewpie doll. As she reaches, the experimenter slowly turns the doll upside down. The child immediately withdraws her hand and stares. Apparently, the view of the doll upside down is so different that the infant responds to the object as if it is a strange new object (Moore, 1979).
Another experiment called the disappearing toy illustrates the child’s tenuous understanding of objects. This is an easy experiment to conduct with infants in the 6-to 11-month age range: Use one of the child’s favourite toys and a kitchen towel. Once you have the infant’s attention, slowly put the toy under the towel. This involves no sleight-of-hand or tricks. The infant is supposed to watch. Now see if the infant can find the toy. Many younger children will reach for the towel but in a moment or two will abandon the search. A 10- month-old will quickly pull the towel away and grab the toy. The two infants have very different reactions to the disappearing toy. Once the toy disappears, the child acts as if it never existed. Out-of-sight, out-of-mind seems to explain the behaviour. Older children seem to be able to hold an image of the toy in memory long enough to conduct a search. They have developed a concept of an object that endures even when the object disappears.
There might be another interpretation for this change in behaviour. It could be that the six-month-old does not have the ability to remove the towel. If this is the case, it is a replay of the flea experiment mentioned earlier. Psychologists are concluding that the infant cannot hold an object in memory, but that is not really the problem. It might be that the towel is too big for the infant to manage. To check this possibility, Gratch covered the toy with a see-through cover. Now the six-month-old infants had no trouble removing the cloth and grabbing the toy (Gratch, 1972). As long as infants could see the object, they reached for it. But when they lost visual contact with it, the object, in effect, disappeared. This experiment demonstrated that six-month-old infants cannot find the object because they have trouble remembering it, not because they cannot remove the towel.
The hide-and-seek technique has been used to explore other facets of the child’s memory. Some researchers have tried to fool the children. They hide a set of keys while the children watch. When the children pull the cloth off, they find a toy car. If the infants are searching for the keys, they should register surprise and keep searching. At nine months, infants do seem confused by this trick, but they do not continue searching. By 18 months, they not only seem perplexed, they continue to search. These children know what went under the cloth and they also know that it still exists somewhere (Gratch, 1979).
The development of an object concept is a landmark in the development of memory. As infants develop more experience with objects, they can represent objects in their minds. This representation is the basis of later symbolic behaviour. Once infants understand that objects and people exist independently, they can engage in much more thoughtful behaviours. An infant can plan actions to accomplish more complex goals. Laurent demonstrates his ability to coordinate different schemes in the following vignette:
At six months I present Laurent with a matchbox, extending my hand laterally to make an obstacle. Laurent tries to pass over my hand, or to the side, but he does not attempt to displace it Finally, at seven months Laurent reacts quite differently almost from the beginning of the experiment. I present a box of matches above my hand, but behind it, so that he cannot reach it without setting the obstacle aside. But Laurent, after trying to take no notice of it, suddenly tries to hit my hand as though to remove it. I let him do it and he grasps the box. (Ginsburg & Opper, 1979, p. 51)
As in Stage 3, the child is behaving intentionally and has a clear goal in mind. But the coordination of schemes that is required in Stage 4 is quite different. The behaviours that Laurent must combine now are much more involved than coordinating the eyes and hands. He must learn how to use his coordinated schemes to get beyond obstacles. This takes thought.
Stage 5: Search for novelty (12 to 18 months): Infants who have a concept of an object and can remember objects, who can plan a course of action, and who are mobile are well prepared to investigate their world. They begin their exploration in earnest during the fifth stage. Using their full repertoire of coordinated schemes such as throwing, dropping, rubbing, and banging, toddlers scrutinize every facet of their environment. Infant explorers like to watch tissues come out of the box, one at a time. They like to flush objects down the toilet, unroll toilet paper, and pour water on the floor. Through these investigations, children discover new information about their environment and new means of accomplishing their goals. When an unfamiliar situation is encountered, as it often is, the child adapts strategies that have worked before.
Jacqueline intentionally let objects she was holding fall to the ground. During her meal, while she is seated, she moves a wooden horse to the edge of her table until she lets it fall. She watches it. An hour later she is given a postcard. Jacqueline throws it to the ground many times and looks for it. She systematically pushes a thimble to the edge of the box on which it is placed and watches it fall. (Piaget, 1952, p. 270)
Those who are familiar with small children will recognize this behaviour as an exceedingly trying one. However, if you recognize the motivation for the infant’s behaviour, the “throw it” or “drop it” game becomes more tolerable. Jacqueline is learning that you do not have to push objects to the ground. They will fall if you simply let go of them. She is using her coordinated schemes to investigate her universe.
Jonas Langer, a Piagetian scholar, believes that the action sequences produced during Stage 5 are the roots of abstract logic. He points out that people sort the world into categories on an abstract level. Objects are identified by color, mass, weight, density, volume, and friction. The logic that underlies these categories can be seen in action sequences similar to Jacqueline’s (Langet, 1980). Infants learn that when they drop different objects, some float downward, others bounce, while still others break. Their action sequences help them form rudimentary classes that will later be transformed into a symbolic classification system.
Infants 9—12 months old will select similar objects to manipulate. When given a tray containing four small plastic human figures and four small red “broom handles,” infants begin to separate the two groups of objects (Starkey, 1981). This is another example of a rudimentary classification system based on the action schemes of the sensory motor period.
Stage 6: Beginning of thought (I8 to 24 months): The emphasis through the fifth stage of sensory motor development is on action. Although we can see the beginnings of representation in the child’s memory of objects, the child still relies on manipulation. However, during the sixth stage, the role of action begins to recede and we see thoughtful assessments assume more importance. The ability to remember something that was not present was first acknowledged with the object concept. At that point, the child’s ability to reconstruct objects was very limited. Now infants not only reconstruct images of people and objects that are absent, they can manipulate these images in their mind. As a result, they can think about problems. The experimenter of Stage 5 gives way to the philosopher of Stage 6. During this final period of sensory motor development, infants, who now know a great deal about the environment, begin to use their information to solve problems.
Laurent is seated before a table and I place a bread crust in front of him, out of reach. Also, to the right of the child I place a stick about 25 centimetres long. At first Laurent tries to grasp the bread without paying attention to the instrument, and then he gives up. I then put the stick between him and the bread. Laurent again looks at the bread, without moving, looks very briefly at the stick, then suddenly grasps it and directs it toward the bread. But he grasped it toward the middle and not at one of its ends so that it is too short to attain the objective. Laurent then puts it down and resumes
stretching out his hand toward the bread. Then without spending much time on this movement, he takes up the stick again, this time at one of its ends, and draws the bread to him. He begins by simply touching it, as though contact of the stick with the objective were sufficient to set the latter in motion, but after one or two seconds at most, he pushes the crust with real intention. He displaces it gently to the right, then draws it to him without difficulty. Two successive attempts yield the same result. (Piaget, 1952, p. 335)
Laurent’s attempts to reach the bread with his hand did not work so he devised an alternate plan. Remember that when the environment does not fit neatly into a child’s structure, the child can alter that structure. Laurent does this and his second plan, using the stick, suggests that he can visualize the stick reaching the bread and bringing it close enough to grab. It is the thoughtful use of the stick that is unique to this stage. Laurent not only visualizes the stick, he imagines how it will help him solve the problem. Being able to transform an image like this gives infants untold flexibility and power. Once children can imagine an object being changed, thoughts cn direct the child’s actions. Prior to Stage 6, the actions of the child helped the child form images. At this point, a revolution occurs and the images and thoughts of the child begin to direct the actions (Ginsburg & Upper, 1979).
To review the changes in the child’s conception of the world, let us look again at newborns. They exercise their reflexes and built-in patterns of behaviour until they gradually gain control over their eyes, hands, and mouth. With a few more weeks of effort, these isolated patterns become coordinated into action schemes. Exploring objects—by seeing them, touching them, and sucking on them—helps infants realize that the people and objects in the environment have an independent existence.
Once children understand that objects have a permanence of their own, they can begin to represent these objects. Now hide-and-seek games reveal the child’s conceptual understanding of the world. Equipped with integrated senses and the ability to remember—at least for short periods of time—the infant investigates the environment with gusto. At the culmination of the sensory motor period, the infant is able to devise new approaches to problems by manipulating the world symbolically rather than physically.
This quick review of two years of concentrated effort on the part of the infant seems to gloss over the incredible changes that take place (see Figure 6—7). At Stage 1, the newborn has little anticipation, intentionality, no words, and no conceptual understanding of how the world functions. A short 18 to 24 months later, infants anticipate, imitate, initiate, have a firm grasp of their immediate environment, can think about different ways to solve a problem, and have a limited vocabulary.
Piaget’s observations, first published in 1936, have stood the test of time. Almost 50 years later, this description still provides an accurate overview of the changes in the infant’s thought patterns. The coordination of schemes, the formation of early memories, the development of the object concept, and the relationship between language and thought are all new areas of research that have grown out of Piaget’s descriptions of the sensory motor period. In addition, extensions of Piaget’s work with infants have been conducted in the areas of vision, memory, learning, and concept development. With these extensions of Piaget’s ideas, our understanding of an infant’s cognitive development has become much more elaborate and detailed. Let us consider some of these recent findings.