Syllabus Edition
First teaching 2025
First exams 2027
Baillargeon’s Theory (AQA A Level Psychology): Revision Note
Exam code: 7182
Infant knowledge & reasoning of the physical world
Baillargeon’s theory of infant knowledge and the physical world is a nativist explanation of early infant abilities
Baillargeon assumed that infants have an inbuilt sense of object permanence, unlike Piaget, who thought that infants acquire object permanence around the age of eight months
Baillargeon believed that infants are born with a ready-made sense of the physical world and that this does not have to be constructed using the ‘building blocks’ of experience
This innate understanding of the physical world was termed the ‘physical reasoning system’ by Baillargeon (2012)
Baillargeon argued that infants are born with a sense of object persistence, i.e., that an object still exists even when it is occluded (blocked) by another object, and so she devised a series of experiments to test this theory
Infants were shown a screen with a window cut into it
Two types of carrots were used:
A tall carrot (which should be visible through the window when it passes by)
A short carrot (which should not be visible through the window when it passes)
Possible event: The short carrot moves behind the screen and isn’t visible in the window — makes sense
Impossible event: The tall carrot moves behind the screen and doesn't appear in the window — this violates expectations
4-month-old babies looked longer at the impossible event, suggesting they were surprised
This indicates they expected the tall carrot to appear in the window — showing:
An understanding that objects continue to exist when out of sight
That hidden objects have properties (like height) that persist even when unseen
Violation of expectation
Violation of expectation (VOE) refers to events which defy logic and do not appear to be physically possible
VOE research depends upon an infant’s innate understanding of the physical world
E.g. If a dog walks behind a fence, I can’t see the dog anymore
Baillargeon researched VOE by setting up a series of experiments in which an infant’s reaction to an impossible event was observed (see above)
An impossible event is one which should not happen if objects/people/animals obey the laws of physics, i.e., solid objects should not be visible if they are obscured by another solid object
Research which investigates Baillargeon’s theory
Bower (1982) – An experiment in which infants’ heart rates were measured during a possible and impossible event: their heart rate increased when presented with an impossible event
Wang et al. (2003) found, via two experiments, that 4-month-old infants show VOE in tasks involving hidden objects even without the usual habituation phase
Aguilar and Baillargeon (1999) - Infants were habituated to the sight of a Minnie mouse toy being passed from one side of a screen to the other using a high window condition (possible event) and a low window condition (impossible event): infants stared at the low window condition more as predicted by VOE
Evaluation of Baillargeon’s Theory
Strengths
VOE is now a widely used technique in research on object permanence/persistence, which means that Baillargeon’s theory is reliable
There is a lack of evidence that understanding of the physical world (e.g., the law of gravity) is not universal; hence, Baillargeon’s theory could be said to cross cultures and apply to all human beings
Limitations
Rivera et al. 1999 suggested that infants spend longer looking at an impossible event due to their preference for observing moving objects more than those that are stationary, e.g., Baillargeon may have been biased when she reported her findings
Using infants as participants is fraught with difficulties: it is almost impossible to truly understand a baby’s behaviour (the baby cannot be asked about their behavioural responses) so the results are open to interpretation
Issues & Debates
Baillargeon’s theory takes a nativist stance, suggesting infants are born with an innate physical reasoning system; therefore, it exemplifies the nature side of the nature vs nurture debate
Baillargeon’s view supports the idea that some cognitive abilities (like object permanence) are biologically programmed and not learned
Baillargeon’s theory takes a nomothetic approach by aiming to establish universal laws of infant cognitive development, such as the idea that all babies are born with a physical reasoning system
This contrasts with idiographic approaches, which would focus on individual differences in infant experience and development, suggesting Baillargeon may underestimate the role of personal variation
Worked Example
Here is an example of an AO3 question that you might be asked on this topic.
AO3: You need to analyse and evaluate key concepts, ideas, theories and research.
Q. Explain one limitation of research on violation of expectation.
[2 marks]
Model answer:
Outline the limitation:
One limitation of research on violation of expectation is that it relies on interpreting infant behaviour, such as how long they look at an event [1 mark]
Explain why this is a limitation:
This is open to researcher bias, as longer looking times may not necessarily indicate surprise — babies might just prefer looking at movement or novelty [1 mark]
Unlock more, it's free!
Did this page help you?
