Lance J. Rips

Central to What Babies Know (Spelke, 2022) is the thesis that infants' understanding is divided into independent modules of core knowledge. As a test case, we consider adding a new domain: core knowledge of substances. Experiments show that infants' understanding of substances meets some criteria of core knowledge, and they raise questions about the relations that hold between core domains.

Readers assume that commonplace properties of the real world also hold in realistic fiction. They believe, for example, that the usual physical laws contin

We think of the world around us as divided into physical objects like toasters and daisies, rather than solely as a smear of properties like yellow and smooth. How do we single out these objects? One theory of object concepts uses part‐of relations and relations of connectedness. According to this proposal, an object is a connected spatial item of maximal extent: Any other connected item that overlaps (i.e., shares a part with) the object must be a part of that object. This article reports four experiments that test this proposal. Participants see descriptions or diagrams of spatial items that vary across trials in their relative positions. In separate experiments, participants decide whether the items are physical objects, whether they are wholes, or how many objects are present. All experiments find support for connectedness as a contributor to object status, but they find little support for maximality. The results suggest that maximality is not a necessary feature of wholes or of objects.

What we know as the self is not just one unified construct, but consists of various self-concepts that are continuously created, revised, and discarded, such as “woman”, “Thai national”, “Northwestern student”, and “true self”. These rich, variegated self-concepts help organize our endeavors throughout the different domains of our lives. How do we store information associated with each of these self-concepts without confusing them in long-term memory? We uncover two mechanisms that support this ability— one that arises from the nature of long-term memory processing, and the other that arises from the nature of self-referential processing. Specifically, people are less likely to confuse memories for self-concepts that are more distinct, and they are more likely to remember information for the self than for others. Together, the studies shed light on the mechanisms that support our impressively rich store of self knowledge.

A cornerstone of cognitive science is that mental systems are limited: There is a maximum amount of information they can process or store, beyond which performance breaks down. Yet so far the study of such limits has been focused on core systems like attention and memory. Here we explore the limit of self-representation, the ability to represent someone or something as you. Using an associative learning paradigm, we find a limit on a well-known index of self-representation known as the self-reference effect, whereby people perform better for items that they represent as themselves than as others. This effect did not continue to scale additively as people associated stimuli with more than one self-identity at a time (e.g., their younger and older selves). This suggests that even though we can represent various identities as the self, we do so independently in serial.

People distinguish objects from the substances that constitute them. Many languages also distinguish count nouns and mass nouns. What is the relation between these two distinctions? The connection...

This article looks at the way people determine the antecedent of a pronoun in sentence pairs, such as: Albert invited Ron to dinner. He spent hours cleaning the house. The experiment reported here is motivated by the idea that such judgments depend on reasoning about identity (e.g., the identity of the he who cleaned the house). Because the identity of an individual over time depends on the causal‐historical path connecting the stages of the individual, the correct antecedent will also depend on causal connections. The experiment varied how likely it is that the event of the first sentence (e.g., the invitation) would cause the event of the second (the house cleaning) for each of the two individuals (the likelihood that if Albert invited Ron to dinner, this would cause Albert to clean the house, versus cause Ron to clean the house). Decisions about the antecedent followed causal likelihood. A mathematical model of causal identity accounted for most of the key aspects of the data from the individual sentence pairs.