Piaget = babies don't reach for a hidden object because they lack an understanding of object permanence
Baillargeon = babies have a better understanding of the physical world than Piaget proposed - their behaviour might be better explained by poor motor skills or being distracted
violation of expectation (VOE) research
Baillargeon developed the VOE technique = to compare babies' reactions to an expected and unexpected event
they were then able to make inferences about the infant's cognitive abilities
Baillargeon and Graber VOE study (procedure)
24 babies (aged 5-6 months) = were shown a tall or a short rabbit passing behind a screen with a window
they were first 'familiarised' with the task and then were shown the test events to see how they would react
expected condition = the tall rabbit can be seen passing the window but the short cannot
unexpected condition = neither rabbit appeared at the window
Baillargeon and Graber VOE study (findings/conclusions)
babies looked at unexpected condition for = average of 33.07 secs
babies looked at expected condition for = average of 25.11 secs
this was interpreted as meaning that the babies were surprised at the unexpected condition
this demonstrates understanding of object permanence at less than 6 months of age
other studies tested understanding of containment and of support
physical reasoning system (PRS)
Baillargeon et al = proposed that we are born with a PRS to enable us to learn details of the physical world more easily
they referred to object persistence = we know that objects do not disappear (similar to Piaget's object permanence)
example:
from birth, babies identify event categories (ways that objects interact) = eg = occlusion occurs when one object blocks another
since babies know about object persistence, they quickly learn that one object can block another (occlusion)
strength = validity of VOE technique
Piaget made a flawed assumption that loss of interest in an object means the baby thinks the object has ceased to exist (the baby may have just been distracted)
Baillargeon's VOE method controls for this because distraction wouldn't affect the outcome
this control of confounding variables means the VOE method has greater validity
counterpoint to validity of VOE technique
Piaget claimed that acting in accordance with a principle is not the same as understanding it
understanding involves being able to think about it consciously
means that babies' responses to unexpected conditions may not represent a change in their cognitive abilities
limitation = the assumption that response to VOE = unexpectedness
a methodological issue is that babies' response may not be the unexpectedness of the event
all the VOE shows is that babies find certain events more interesting
we are inferring a link between this response and object permanence
actually the different levels of interest in the two different events may be for any number of reasons
means that the VOE method may not be a valid way to study a young child's understanding of the physical world
strength = PRS can explain why physical understanding is universal
we all have a good understanding of the physical world regardless of culture and experience
eg = so if we drop a key ring, we all understand that it will fall to the ground
this universal understanding suggests that a basic understanding of the physical world is innate (otherwise we would expect cultural and individual differences)
means that Baillargeon's PRS appears to be a good account of infant cognitive abilities
extra evaluation = credibility
there have been challenges to the PRS = it is hard to determine whether a baby is really responding to the unexpected nature of an event, and even if it is this may not indicate understanding
HOWEVER = the idea of the PRS fits with what we already know about development of other visual systems (eg distance perception)