Baillargeon’s Theory (AQA A Level Psychology): Revision Note

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 et al. (2012) proposed that humans are born with a physical reasoning system (PRS)

  • This is an innate, primitive awareness of the physical properties of the world, which becomes more sophisticated as infants learn from experience

• The PRS predisposes infants to attend to events that violate physical laws (impossible events), and it is this attention that allows them to develop their understanding of the physical world

  • Understanding develops one event category at a time

    • E.g. occlusion is understood very early, which is why even young infants can succeed in tasks involving hidden objects

• Baillargeon argued that infants are born with a sense of object persistence, i.e., that an object still exists even when it is occluded by another object, and so she devised a series of experiments to test this theory

Baillargeon & DeVos, 1991

• 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

• The VOE method is a better test of infant understanding than Piaget's as Piaget assumed that a baby switching attention away from a hidden object no longer knew it existed, but the baby may simply have lost interest

  • VOE eliminates this confounding variable as losing interest cannot explain why infants look longer at impossible events, giving the method better validity than alternatives

• Hespos & van Marle (2012) point out that, without learning, everyone shares a basic understanding of the physical properties of the world, e.g., we all know that a dropped set of keys will fall to the floor

  • No cultural differences in basic physical understanding have been found, and this universality strongly suggests that the PRS is innate, as Baillargeon claimed

Limitations

• It is hard to judge what an infant actually understands: infants may look longer at one event simply because they find it more interesting

  • E.g., Rivera et al. (1999) suggested a preference for movement could explain longer looking times

    • This means longer looking may not indicate surprise at physical impossibility, so the VOE method may not be an entirely valid way of investigating infant understanding

• Using infants as participants is fraught with difficulties: a baby cannot be asked about their behavioural responses, so researchers must infer understanding from behaviour alone, and these inferences are open to interpretation

  • This means conclusions about what infants 'know' may reflect the researcher's assumptions as much as the infant's actual cognitionIssues & Debates

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