Pre-Operational Stage (2-7 Years)
Cognitive Development
Pre-operational stage (2-7 years)
Preconceptual thought (2-4 years)
Intuitive thought (4-7 years)
(Piaget notes and Sroufe, Ch. 9)
Characteristics of preschooler’s thinking according to Sroufe:
§ Children continue to be active participants in their own development
§ A continual interplay between children’s developing capacities and the environment
§ Specificity vs. generality – domain and cultural specificity – acquisition of concepts and skills in specific domains.
§ Cognitive limitations – difficulty integrating multiple pieces of information, centration, appearance-reality problem, difficulty managing attentional and memory processes, egocentrism (not as serious as Piaget thought).
For Piaget, stage is marked by transition from egocentric to social behavior, sociocentric speech and conceptual thought. Onset of symbolic thought and functions.
First indication of symbolic thought involves representing one thing by means of something else.
Less context-bound - extracts concepts from experience.
Lid of box symbolized by opening and closing hand, or eyes, or mouth - use of different mediums.
Carry it with us. Reference to box when absent.
Focuses attention of others on a particular characteristic
Malleable - can experiment with form of reality.
Imaginative play now possible.
We also see the onset of delayed imitation. Detaching thought from action – more efficient thinking.
Language is the following step - reconstructing past, planning, think of distant objects, talk of things not immediately present.
Piaget did not believe that language plays a major role in cognitive development. Sensorimotor activity does, and provides the foundation for language. Language is not necessary for logical categories – these appear before language.
The child still cannot, however, form a whole representation. 4-5 year olds still cannot reconstruct their way to school when asked.
Reasoning is characterized as transductive - reasoning by simile.
Children are still egocentric - can't completely imagine what can be seen from another perspective.
Children do not have the concept of conservation, at least not full-blown. Reason from configuration, not transformation. Can't perform the cognitive operation of reversal.
1. dependent on sensory experiences
2. focuses on 1 aspect of problem
3. does not rearrange information in mind.
In sum, Piaget listed three important more specific limitations of the child's ability to think logically:
1. centration - tendency to consider only one piece of information when multiple pieces are relevant.
Liquid conservation experiment.
2. appearance-reality problem - the tendency to define reality by surface appearance. Perception-bound
The sponge rock experiment.
3. Focus on states rather than transformation.
4. Irreversibility – not present – we can’t imagine a reversal in a state of affairs.
5. egocentrism - seeing the world from their own viewpoint and inability to take the perspective of another person. Interpret world in their own terms.
Difficulty in speaking about other perspectives.
The collective monologue.
Parallel play - two children in their own separate worlds.
Mountain experiment - cannot do this correctly until they are 8 years old. Children under 6 will choose their own view.
4. memory limitations - not specifically addressed by Piaget, but more by the information-processing approaches. Difficulty with tasks that require memory strategies or other activities to enhance memory.
Children’s thinking becomes more and more decontextualized.
Make-believe play
For Piaget, play was practice of representational schemes. Make-believe play not only reflects, but contributes to cognitive social skills.
The Development of make-believe –
1. Over time, play becomes increasingly detached from the real-life conditions associated with it.
Toddlers – use only realistic objects – try telephone, toy cup.
2 yrs. – less realistic toys – block for phone
3rd year – imagine objects and events without support from real world – invent kithen.
A play symbol no longer must repressnt the object for which it stands.
2. The way the “child as self” participates in play changes with age.
Failing to Reason or Failing to Understand?
(M. Donaldson)
Making a "deductive inference" is the drawing of a conclusion if something is true, then something else must be true.
Transitivity problem: If A>B, and B>C, then A must be greater than C (give concrete example)
The truth of the first two statements - the premises - makes the truth of the third statement - the conclusion - necessary. Nothing else is possible. The truth of the first two statements is incompatible with the third.
Key notions: necessity, possibility, and compatibility.
Compatibility is basic - understanding that we live in a world where the existence of one state of affairs may sometimes rule out the existence of another. The basis for deductive reasoning.
Learning language is a matter of understanding compatibility.
Using language to describe requires recognition that certain states of affairs cannot exist together.
"That's bow-wow" indicates one of many possibilities - incompatible with many others that could have been said.
To assert is simultaneously to deny.
When kids begin to use language we see that they have only a dim awareness of what a statement can include or what it can't.
"dog" is not incompatible with brown, small, furry, etc.
Compatibility is not the only necessary thing for being able to think deductively - Piaget also says that a child has to be able to decentre and to be able to distinguish appearance from reality.
Causal Reasoning
Different types of reasoning. (see handout)
Piaget’s characterization of children’s causal reasoning
Immanent justice - ways of interpreting misfortune
Why did you fall? "Because children are not supposed to run fast".
Why did you get burned? "Because children are not supposed to play near the stove".
Animism - attribution of life to inanimate objects. Sun is angry at clouds, or sun goes to sleep.
Artificialism - everything designed by humans or by God.
See handout.
Different levels in the use of these types of explanations have been identified
1. Influenced by superficial appearance of things (“clouds move when we move”)
2. appeal to all-powerful force that controls objects and events (God, or mom and dad) - Artificialism
3. Begin using causes in nature to explain natural phenomenon (rays of the sun pushing the clouds)
4. Approaching an adult explanation, though explanation is still incomplete (“they have a current”)
Piaget did not find mature reasoning about causation until middle childhood, but it depends on the complexity and familiarity of the problem Three year olds learn about cause-and-effect relationships in simple situations.
Children may not understand what a “good” explanation from an adult point of view is. May invent reasons when they don’t know the answer. Lack an abstract idea of what constitutes a plausible cause.
Magic – children between 3 and 4 may use supernatural explanations for seemingly impossible events, but don’t use it as a general explanation for processes they don’t understand.
Reasoning About Living and Nonliving Things
The use of animism is not as pervasive as Piaget thought, but children do have trouble distinguishing between living and nonliving things. E.g. category of living things may include all types of animals, but not plants.
Until about age 6, they do not have a specific, consistent, and coherent understanding of living vs. non-living things with all the qualities.
Reasoning About Quantity
Rules of conservation - the understanding that certain characteristics remain unchanged despite transformations carried out on them. Conservation of liquid volume, number, mass, length.
Liquid conservation failure highlights two limitations on child's thinking:
1. misled by appearance of liquid in tall glass - mistake superficial appearance for reality.
2. focus on only one aspect of the stimulus, the height of the water.
Most children don't grasp conservation completely until the elementary school years, around 7.
Stages in the development of conservation:
1. non-conservers – 3-4 year olds. Using the rule “higher is more”
2. transitional period – 5-6 year olds. Less decisive. Aware that their answers may be wrong and are looking for a consistent rule to apply,
3. mature conservation – 7 years old. Now answer quikly and confidently. Previous answers seem stupid.
Compensation – now takes 2 factors into account – height & width
Reversibility – undoing the change – can pour it back
Nothing added or subtracted – lack of relevant change. Also called “identity” – “you can pour it back”.
Conservation of liquid volume, number, mass and length do not emerge all together. Liquid volume is often the first to be learned.
There is evidence that particular experiences influence how fast conservation is learned. In pottery-making families in Mexico conservation of mass is learned faster.
Can conservation be taught?
Just explaining conservation to children does not seem to work. Training (learning situations) can help sometimes, especially with older preschoolers, but effects are unstable. Suggests that an overall cognitive framework is necessary, like Piaget said.
Bruner’s screen test – pre and post test with traditional question. Pouring done with glasses behind a screen.
4 yr. – no conservation on pre or posttest. 50% on screen test. Answers seem to be guessing, and they seem to depend on appearance.
6 yr. – drastic improvement on screen test and maintained it on posttest.
Gold and number conservation – training kids to count rather than depend on length helps with older preschoolers, but does not last (Gelman).
Easier testing situations
The one-question study.
Concepts of Number
An awareness of “how many” items are present and of how addition, subtraction, and rearrangement affect this number.
Piaget’s original task – child shown two rows of seven coins, arranged so they are the same length. Coins spread out. Longer row seems to have more.
Cooper's dolls in the bed study. Only used 4 dolls in beds. Using fewer objects makes the task easier. Even 4-yr.-olds understand.
Understanding the effects of addition and subtraction
Gelman’s mice study – showed children 2 plates, one containing a row of two toy mice, the other a row three. Children played a game in which they had to identify the “winning” plate. Pointed to plate that had three mice and said it would always be winner, but didn’t say why. Covered plates and shuffled them. Uncovered them and child had to say which was the winner. After winning several times, she changed the plate with three mice, either removing a mouse or moving the mice closer together or farther apart. She found that 3 & 4 year olds could understand which plate was a “winner” by the number of mice on it.
Cooper – children presented with two groups of objects which initially were equal in number, differed by 1 or by 2. Then an object was either added to one of the groups or taken away. Children then had to say which had more.
All children understood that adding increases and subtracting decreases. However, 2 & 3 year olds always said the group added to had more regardless of how many there were to begin with (primitive rule). (“More than there was before”)
4 & 5 yr. olds took into account the initial size (greater than, less than, equal to) but not the absolute number in each group (qualitative rule), e.g. when used groups of 5 & 7 objects, when 1 was added to the 5, they said they were equal.
6 & 7 year olds used a quantitative rule, and correctly took into account the magnitude of the differences between groups.
These “stages” also coincide with number conservation, suggesting that counting and conservation of number go together, however, it occurs earlier than Piaget said.
Learning to Count
One-to-one principle – idea that each member of a set is paired with 1 and only 1 number name. 2-3 yr. Old have difficulty when counting more than 3 or 4 objects. Count some twice, skip some, especially when not arranged in a row.
Stable-order principle – idea that number names occur in a certain order when paired with objects. Younger children sometimes show idiosyncratic orders – leave out numbers sometimes.
Cardinal principle- idea that final word in a counting sequence describes total number in set. Appears after age 3.5. At 3 it works for 2-3 objects, but not more. More evident by age 4.
Abstraction principle – idea that any set of objects is countable.
Order-irrelevant principle – idea that it does not matter in what order things are counted. Counting sets of objects in different order the second time. Appears by age 5.
Concepts of Measurement
Piaget believed that learning about conservation was required to understand measurement. Yet preschoolers show an intuitive grasp of measurement before they correctly solve conservation problems.
Young children will divide a string in half. Can form 2 equal groups of cookies.
Errors – when 2 equal quantities look unequal (e.g. when two strings of equal length are side by side but one is wavy and the other straight, they say the straight is longer.
They understand relative size (<, >, =) or qualitative relations but not quantitative. No grasp of units of measurements like inches or meters.
Preschooler's also appear to have a concept of number, and concept of measurement, earlier than Piaget thought. They demonstrate this in conditions in which there is no misleading perceptual information.
They do not however, have a systematic understanding of quantity.
Summary – four basic points
1. Preschoolers do not usually display an understanding that quantities are conserved despite changes in appearance.
2. When they do not grasp conservation, they tend to focus on one aspect of the problem. Immediate appearance seems to be what counts.
3. Teaching can help, but not before child has the cognitive framework.
4. Failure to understand conservation does not prevent children from learning a lot about counting, measurement, and small quantities, and about how numbers can be changed through addition and subtraction.
5. Preschoolers show considerable sophistication in reasoning about small numbers.
Classes and Collections
A class is any set of objects or events that we think of as having certain features in common and therefore as being the same in certain ways.
First step in infancy, when they treat certain stimuli as the same based on shared characteristics. A morphological classification.
Toddlers are actively sorting objects on the basis of common properties.