Ability to think
logically about physical
changes and relations
7-13 years
Formal
Operations
Abstract and
hypothetical
reasoning
Cognition at
different ages
6 months
Infants appreciate difference between selves and
objects but do not understand continued
existence of objects beyond their own actions
9-18 months
Infants develop an imperfect
understanding of the continued
existence of objects once occluded
Birth
Infants have no understanding of the world
Stage 3 error
Babies of 6-9 months fail to search for
occluded objects but do search for partly
concealed objects. Piaget concluded that
they do not understand the covered object
still exists, and when they uncover the partly
concealed objects, they believe their own
actions reconstitute the object
Stage 4 error
Infants of ~9 months retrieve a covered object at
location A, but when it is hidden at location B, fail to
search for it. Piaget concluded that the child does not
understand that the object can exist elsewhere other
than the place they originally uncovered it- it becomes a
"thing of the place". They believe their own actions will
reconstitute it regardless of where they search
Tests of infant cognition
Preferential looking
Preferential looking experiments
compare how long infants look at two
stimuli as a measure of surprise or
preference
If there is a positive result, the
infant can evidently distinguish
between the stimuli and
conclusions can be drawn. If there
is a null result, it cannot be
established whether they have no
preference or simply cannot
distinguish them
Can conclusions be drawn? Is "surprise" the correct
interpretation of the results? Could it not be to do with
increased perceptual information
Experiments
where this is
used
Baillargeon et al: drawbridge
experiments. Longer looking
time at impossible event
suggests surprise and
therefore understanding of
basic object properties
Kellman and Spelke:
Infants recognised
continuity of partially
concealed rod (looked
for longer at
unexpected event)
Habituation
Habituation involves showing
infants a stimulus until looking
time decreases by 50%, then
showing them novel stimuli
Again, conclusions
cannot be drawn from
null results
Used in
Baillargeon
experiment
A not B error
Infants of ~9 months retrieve a
covered object at location A,
but when it is hidden at
location B, fail to search for it.
Piaget concluded that the child does not
understand that the object can exist elsewhere
other than the place they originally uncovered
it- it becomes a "thing of the place". They
believe their own actions will reconstitute it
regardless of where they search
Alternative suggestions for error
Lack of motor
co-ordination to alter
response
Memory deficits
Although error is made
when object hidden
under transparent
cover
Misunderstanding
of task or
confusion
Conservation
Piaget
For conservation to occur, children must recognise the
reversibility of the transofrmation. This means they need to
decentre their attention from one dimension. Young children
lack reversibility because they cannot think logically about
physical changes
Piaget concluded from the
results of conservation tasks
in young children that they
lack reversibility due to
egocentrism
Reversibility, Egocentrism
and the Principle of
Invariance
Reversibility is the ability to
manipulate mental representations
of objects
Egocentrism is the inability to
consider objects or scenes from a
different spatial or temporal
perspective
The Principle of
Invariance states that
there are relevant and
irrelevant changes
associated with an
object
(addition/subtraction
vs perceptual
transformations)
Three Mountains Task
Criticisms of Piaget
Naughty teddy
Suggests results of conservation
experiments may have been due
at least in part to demand
characteristics
Neonate
conservation
Newborn babies act
surprised when basic
conservation is
violated