AQA Syllabus focus:
'Baillargeon’s explanation of early infant abilities, including knowledge of the physical world.'
Baillargeon argued that even very young infants have a basic understanding of how objects behave.
Diagram of Baillargeon’s classic violation-of-expectation “drawbridge” setup, contrasting a physically possible event (screen stops at the hidden box) with an impossible event (screen appears to rotate through the box). This visual helps you link longer looking times to infants’ early expectations about object solidity and persistence, even when the object is occluded. Source
Her explanation suggests infant cognition is richer than once believed and includes early expectations about the physical world.
Baillargeon’s view of infant knowledge
Baillargeon challenged the idea that infants begin life with very little understanding of objects. She argued that babies do not simply learn all physical rules slowly through action alone. Instead, they appear to bring basic expectations to new situations and use these expectations to interpret what they see.
In this account, infants are not miniature scientists with a full adult understanding of physics. Their knowledge is simple, early, and specialized. It helps them make sense of objects, movement, and stability long before they can explain these ideas in words.
Baillargeon’s explanation is often linked to a nativist view of development. This means some understanding of the physical world is present very early, rather than being built entirely from scratch after birth.
Core principles of the physical world
Baillargeon often describes this early understanding as part of core knowledge.
Core knowledge: A set of basic, early-emerging mental structures that give infants simple expectations about important aspects of the world, especially objects and their behavior.
This means infants do not face the physical world as a completely blank slate. They already expect some regularity in how objects behave.
Objects are cohesive wholes
One important expectation is that objects are bounded, solid units. An object should stay together as a single thing rather than breaking apart for no reason. This is sometimes described as cohesion. If part of an object is visible, infants treat it as belonging to one continuing whole.
This matters because it allows infants to represent objects as stable entities rather than disconnected bits of color or shape. It is a basic foundation for understanding the physical environment.
Objects move in continuous ways
Infants also seem to expect objects to move along continuous paths through space and time. In other words, an object should travel from one place to another in a connected way, not disappear from one point and instantly appear somewhere else without a plausible route.
A related expectation is that physical objects do not usually change position unless there is an appropriate contact or force involved. Objects should not start moving by themselves in ordinary physical events. These expectations help infants interpret movement as ordered and lawful rather than random.
Objects cannot occupy the same space and need support
Baillargeon’s explanation also includes the idea that objects obey basic limits. One object should not simply pass through another solid object. Similarly, an object that is not adequately supported should not remain suspended in midair.
These expectations show that infants have some sensitivity to solidity and support. They do not yet understand mechanics in an adult way, but they do seem to have early rules for what counts as a possible or impossible physical event.
How physical knowledge develops
Baillargeon did not argue that all physical knowledge is complete at birth. Instead, she suggested that infants begin with broad principles and then gradually refine them through experience.
Physical reasoning: The use of basic knowledge about objects to interpret and predict physical events, such as movement, collision, support, and containment.
As infants gain experience, they become better at noticing which features of an event are important. Baillargeon proposed that they learn specific variables that matter in different kinds of situations.
For example, in one type of event the amount of support may be crucial, while in another the height, width, or position of an object may be more important.
This means development is not all-or-nothing. Infants may show impressive understanding in one physical context but more limited understanding in another. Their knowledge becomes more accurate as they discover which details are relevant for each event category.
Why Baillargeon’s explanation is important
Baillargeon’s account changes how psychologists think about infancy. It suggests that poor performance on some tasks does not necessarily mean no understanding. An infant may know something about objects but still fail a task because of memory limits, attention demands, or immature motor control.
This distinction is important because it separates competence from performance. Competence refers to what an infant understands, while performance refers to what the infant can actually show in a particular situation. Baillargeon’s explanation therefore presents infancy as a period of earlier and richer cognitive ability than was once assumed.
Her ideas also support the broader claim that some parts of cognition are domain-specific. Rather than developing through one general thinking system alone, infants may have specialized systems for reasoning about different areas of experience. Knowledge of the physical world is one of these areas.
Limits of early physical knowledge
Although Baillargeon emphasized early ability, she did not claim that infants possess adult-like science. Early knowledge is basic and often fragile. Infants can miss important variables, especially when events are complicated or unfamiliar.
Their expectations are also mostly implicit. Young infants cannot state physical rules verbally or consciously justify them. Instead, their knowledge is shown through how they attend to and interpret events.
Baillargeon’s explanation therefore presents infant understanding of the physical world as early but incomplete. Babies seem prepared to understand objects as cohesive, continuous, solid, and support-dependent, but experience is still necessary to refine and extend this knowledge.
Practice Questions
Identify one principle in Baillargeon’s explanation of infants’ knowledge of the physical world. (2 marks)
1 mark for identifying a correct principle, such as cohesion, continuity, solidity/contact, or support.
1 mark for a brief accurate explanation of that principle.
Explain Baillargeon’s explanation of early infant knowledge of the physical world. (6 marks)
Award 1 mark for each accurate point up to 6 marks:
Infants have early knowledge of the physical world.
This knowledge is often described as core knowledge.
It is present very early and is usually seen as at least partly innate.
Infants expect objects to be cohesive wholes.
Infants expect objects to move in continuous paths.
Infants expect objects not to pass through other solid objects.
Infants expect objects to need appropriate support.
Experience helps infants learn which variables matter in different physical events.
Early knowledge is basic and implicit, not full adult understanding.
FAQ
Understanding and action do not develop at exactly the same rate. An infant may have a basic expectation about an object but still struggle to show that knowledge in a task requiring precise movement.
Reaching also depends on attention, memory, inhibition, and motor coordination. If any of these are weak, behavior may look less advanced than the infant’s actual understanding.
An instinct usually refers to a fixed, automatic behavior pattern. Baillargeon’s view is different because it focuses on expectations or representations about how objects should behave.
So the claim is not that infants are programmed to perform one exact action. Instead, they are thought to begin life with mental structures that help them interpret physical events.
Psychologists often look at events involving:
Occlusion: one object moving behind another
Containment: one object placed inside another
Support: whether an object should stay balanced
Collision: what happens when objects make contact
These event types are useful because they reveal whether infants expect objects to remain whole, move continuously, need contact, or require support.
A critic might argue that infants do not need inborn physical knowledge. Instead, they may learn very quickly from repeated visual experience in the first months of life.
Such critics also suggest that some infant responses could be explained by attention, novelty, or perceptual preference rather than genuine understanding of physical rules.
Yes. Even if some physical expectations are early, daily experience can make them more precise. Infants constantly watch objects being dropped, hidden, stacked, or moved.
Caregivers also create learning opportunities through play. Actions like rolling a ball, placing blocks on top of each other, or taking toys out of containers may help infants refine their physical reasoning.
