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We are interested in what infants know about the world. In particular, we examine what infants know about others’ goals and perceptions as well as the physical world.
Most of our studies are looking-time studies. In these studies, the parent will be holding the infant and sitting in front of a puppet stage. We show different events on the stage to the infants, measure their looking times, and videotape their responses. The reasoning is as follows. Infants, like us, usually look longer at events that are unexpected than at expected ones. Therefore, by finding out what events infants identify as unexpected (by looking a long time), we get to know what expectations or knowledge infants hold. For example, if infants look long at an event in which an object disappears out of thin air, we know that infants may realize that all objects should exist continuously and thus cannot pop out of existence. Below is the description of some of our studies.
Infants’ psychological understanding
People’s goals and perceptions
In this line of research, we are interested in whether infants as young as 3 months of age can consider others’ goals and perceptions to make sense of others’ actions. We already know that when infants understand that a person has a preference for toyA over toyB (e.g., she always reaches for toyA as opposed to toyB), they will be surprised when the person later changes her mind to obtain toyB. But what if toyB was initially hidden from the person? Would infants realize that the person could approach either toy when toyB was later revealed? How would infants understand that toyB is hidden from the person? Would they realize that the person cannot see the toy hidden behind a tall but not a short screen? Would they also recognize that the person cannot see the toy positioned behind her back? On the other hand, what if toyB was partly visible to the person? Would infants realize that the specific part of toyB the person can see determines her knowledge of this toy?
Other self-propelled objects’ goals and perceptions
As adults, we attribute goals and perceptions to people as well as other animals. For example, when seeing an ant drag a dead insect across a sidewalk, we assume that the ant is bringing the insect back to its nest to feed other ants and it can somehow perceive its way back. Do infants also attribute goals and perceptions to objects that, like people, move on their own?
We already know that 5-month-old infants attribute goals to the actions of a self-propelled box. After the box repeatedly approaches one of two objects, the infants are surprised when the box changes its “mind” to approach the different object. Would infants younger than 5 months respond similarly in a situation like this? How would infants think about the box’s perceptions? Would they also realize that the box cannot perceive an object hidden behind a screen and hence cannot detect the object’s presence?
Infants’ physical understanding
We know that infants as young as 2.5 months have some understanding about object permanence. For example, they know that when an object is hidden behind an opaque screen or inside an opaque container, it continues to exist even though they don’t see it. However, this does not apply to transparent screens or containers. Obviously, what you see is what you get. Infants have to think differently about transparent screens and containers. When do they do this? In this line of research, we are looking at when infants will be surprised to see an object disappear and reappear magically behind a transparent screen or inside a transparent container.
When would infants realize that like solid objects, liquids also exist and move continuously in time and space? In this line of research, we find that at least by 12.5 months, infants recognize that liquids cannot inexplicably disappear and reappear.
Infant Cognition Lab
Last modified: 06-Feb-2008