Jaswal, V. K., Pérez-Edgar, K., Kondrad, R. L., Palmquist, C. M., Cole, C. A., & Cole, C. E. (2014). Can't stop believing: Inhibitory control and resistance to misleading testimony. Developmental Science. [doi for full text][Abstract]
Why are some young children consistently willing to believe what they are told even when it conflicts with first-hand experience? In this study, we investigated the possibility that this deference reflects an inability to inhibit a prepotent response. Over the course of several trials, 2.5- to 3.5-year-olds (N = 58) heard an adult contradict their report of a simple event they had both witnessed, and children were asked to resolve this discrepancy. Those who repeatedly deferred to the adult's misleading testimony had more difficulty on an inhibitory control task involving spatial conflict than those who responded more skeptically. These results suggest that responding skeptically to testimony that conflicts with first-hand experience may be challenging for some young children because it requires inhibiting a normally appropriate bias to believe testimony.
Eyden, J., Robinson, E. J., Einav, S., & Jaswal, V. K. (2013). The power of print: Children's trust in unexpected printed suggestions. Journal of Experimental Child Psychology, 116, 593-608. [doi for full text] [Abstract]
How do children evaluate the veracity of printed text? We examined children's handling of unexpected suggestions conveyed via print versus orally. In Experiment 1 (N = 131), 3- to 6-year-olds witnessed a speaker either read aloud an unexpected but not completely implausible printed label (e.g., fish for a bird-like animal with some fish features) or speak the label without accompanying text. Pre-readers accepted labels in both conditions. Early readers often rejected spoken labels yet accepted them in the print condition, and in Experiment 2 (N = 55) 3- to 6-year-olds continued to apply them even after the print was obscured. Early readers accept printed testimony that they reject if only spoken, and the influence of text endures even when it is no longer visible.
Akhtar, N., & Jaswal, V. K. (2013). Deficit or difference? Interpreting diverse developmental paths: An introduction to the special section. Developmental Psychology, 49, 1-3. [doi for full text] [Abstract]
How should differences between "typically developing" children and other populations be interpreted? To what extent should the emphasis be on advocating remediation for children who are on a developmental trajectory that differs from the norm versus embracing different developmental trajectories as equally valid contributions to the diversity of human experience? The 6 target articles and 2 commentaries in this special section offer a diverse set of perspectives on the tensions and responsibilities inherent in interpreting and acting on differences between children of different cultural, ethnic, linguistic, socioeconomic, and neurological backgrounds.
Errors can differ in how serious they are. We asked whether preschoolers would use the magnitude of an informant's errors to decide if she would be a good source of information later. 4- and 5-year-olds heard two informants incorrectly label familiar objects, but one informant's errors were closer to the correct answer than the other's (e.g., one referred to a comb as a brush and the other referred to the same comb as a thunderstorm). When the informants had an unambiguous view of the objects, children could identify which informant was closer to being correct, but they did not selectively favor novel labels the "closer" informant later provided. When the informants had only an ambiguous view of the objects (e.g., only the handle of the comb was visible), children did prefer the novel labels the "closer" informant later provided. Preschoolers are willing to overlook semantic errors that are close to being correct, but only when there is an understandable reason why the speaker erred.
How can you tell whether someone knows something? One strategy available early in development involves monitoring whether that person had access to the information in the first place (e.g., Onishi & Baillargeon, 2005). But this strategy is clearly fragile: Children who have a piece of knowledge sometimes mistakenly assume that ignorant individuals share that knowledge (e.g., Birch & Bloom, 2003). Here, we provide the first demonstration that the gesture an informant uses can also cause children to over-estimate her knowledge. Specifically, we found that pointing can lead 3- and 4-year-olds to attribute knowledge to individuals they otherwise recognize are ignorant. Further, we show this effect is specific to pointing: Grasping, another intentional, object-directed gesture, does not lead children to misattribute knowledge.
Palmquist, C. M., Burns, H. E., & Jaswal, V. K. (2012). Pointing disrupts preschoolers' ability to discriminate between knowledgeable and ignorant informants. Cognitive Development, 27, 54-63. [doi for full text] [Abstract]
By 4 years of age, children have been reinforced repeatedly for searching where they see someone point. In two studies, we asked whether this history of reinforcement could interfere with young children's ability to discriminate between a knowledgeable and an ignorant informant. Children watched as one informant hid a sticker while another was turned around, and then both informants indicated where they thought the sticker was, either by pointing or by using a less practiced means of reference. Children failed to discriminate between the two informants when they pointed, but they chose the location indicated by the knowledgeable informant when the informants used a cue other than pointing. Pointing can disrupt as basic an understanding as the link between seeing and knowing.
This experiment tested how 18-month-old infants' prior experience with an object affects their imitation. Specifically, we asked whether infants would imitate an adult who used her head to illuminate a light-box if they had earlier discovered that the light could be illuminated with their hands. In the Self-Discovery condition, infants had the opportunity to freely explore the light-box; all infants used their hands to activate the light-box at least once during this period. The experimenter then entered the room and, while providing explicit pedagogical cues, demonstrated illuminating the light-box using her forehead. In the Demonstration Only condition, infants just viewed the experimenter's demonstration. During a subsequent testing phase, infants in the Demonstration Only condition were more likely to use their foreheads to activate the light-box. Conversely, infants in the Self-Discovery condition were more likely to use their hands, suggesting that efficiency can "trump" pedagogy in some observational learning contexts.
Tenney, E. R., Small, J. E., Kondrad, R. L., Jaswal, V. K., & Spellman, B. A. (2011). Accuracy, confidence, and calibration: How young children and adults assess credibility. Developmental Psychology, 47, 1065-1077. [doi for full text] [Abstract]
Do children and adults use the same cues to judge whether someone is a reliable source of information? In four experiments, we investigated whether children (ages 5 and 6) and adults used information regarding accuracy, confidence, and calibration (i.e., how well an informant's confidence predicts the likelihood of being correct) to judge informants' credibility. We found that both children and adults used information about confidence and accuracy to judge credibility; however, only adults used information about informants' calibration. Adults discredited informants who exhibited poor calibration, but children did not. Requiring adult participants to complete a secondary task while evaluating informants' credibility impaired their ability to make use of calibration information. Thus, children and adults may differ in how they infer credibility because of the cognitive demands of using calibration.
Koenig, M. A., & Jaswal, V. K. (2011). Characterizing children's expectations about expertise and incompetence: Halo or pitchfork effects? Child Development, 82, 1634-1647. [doi for full text] [Abstract]
Do children expect an expert in one domain to also be an expert in an unrelated domain? In Study 1, 3- and 4-year-olds learned that one informant was an expert about dogs relative to another informant. When presented with pictures of new dogs or of artifacts, children who could remember which informant was the dog expert preferred her over the novice as an informant about the names of dogs, but they had no preference when the informants presented artifact labels. In Study 2, children learned that one informant was incompetent about dogs whereas another was neutral. In this case, children preferred the neutral speaker over the incompetent one about both dogs and artifacts. Taken together, these results suggest that for children, expertise is not subject to a "halo effect," but incompetence may be subject to a "pitchfork effect."
Joh, A., Jaswal, V. K., & Keen, R. (2011). Imagining a way out of the gravity bias: Preschoolers can visualize the solution to a spatial problem. Child Development, 82, 744-750. [doi for full text] [Abstract]
Can young children visualize the solution to a difficult spatial problem? Forty-eight 3-year-olds were tested in a spatial reasoning paradigm in which they were asked to predict the path of a ball moving through one of three intertwined tubes. One group of children was asked to visualize the ball rolling down the tube before they made their predictions, a second group was given identical instructions without being asked to use visual imagery, and a third group was given no instructions. Children in the visualization condition performed significantly better than those in the other conditions, suggesting that encouraging young children to use visual imagery may help them to reason through difficult problems.
Jaswal, V. K., Croft, A. C., Setia, A. R., & Cole, C. A. (2010). Young children have a specific, highly robust bias to trust testimony. Psychological Science, 21, 1541-1547. [doi for full text] [Abstract]
Why are young children so willing to believe what they are told? In two studies, we asked whether it is because of a general, undifferentiated trust in other people or a more specific bias to trust testimony. In Study 1, 3-year-olds heard an experimenter claim that a sticker was in one location when it was actually in another, or they saw her place an arrow on the empty location. All children searched in the wrong location initially, but those who heard the deceptive testimony continued to be misled whereas those who saw her mark the incorrect location with an arrow quickly learned to search in the opposite location. In Study 2, children who could both see and hear a deceptive speaker were more likely to be misled than those who could only hear her. Three-year-olds have a specific, highly robust bias to trust what people—particularly visible speakers—say.
How do children resolve conflicts between a self-generated belief and what they are told? Four studies investigated the circumstances under which toddlers would trust testimony that conflicted with their expectations about the physical world. Thirty-month-olds believed testimony that conflicted with a naive bias (Study 1), and they also repeatedly trusted testimony that conflicted with an event they had just seen (Study 2)—even when they had an incentive to ignore the testimony (Study 3). Children responded more skeptically if they could see that the testimony was wrong as it was being delivered (Study 3), or if they had the opportunity to accumulate evidence confirming their initial belief before hearing someone contradict it (Study 4). Together, these studies demonstrate that toddlers have a robust bias to trust even surprising testimony, but this trust can be influenced by how much confidence they have in their initial belief.
Williamson, R. A., Jaswal, V. K., & Meltzoff, A. N. (2010). Learning the rules: Observation and imitation of a sorting strategy by 36-month-old children. Developmental Psychology, 46, 57-65. [pdf] [Abstract]
Two experiments investigate the scope of imitation by testing whether 36-month-olds can learn to produce a categorization strategy through observation. After witnessing an adult sort a set of objects by a visible property (their color, Experiment 1) or a non-visible property (the particular sounds produced when the objects were shaken, Experiment 2), children showed significantly more sorting by those dimensions relative to children in control groups, including a control group in which children saw the sorted endstate but not the intentional sorting demonstration. The results show that 36-month-olds can do more than imitate the literal behaviors they see; they also abstract and imitate simple rules that they see another person use.
When they see a familiar object and an unfamiliar one, and are asked to select the referent of a novel label, children usually choose the unfamiliar object. We asked whether this 'disambiguation effect' reflects an expectation that each object has just one label (mutual exclusivity), or an expectation about the intent of the speaker who uses a novel label. In Study 1, when a speaker gazed at or pointed toward the familiar object in a novel-familiar pair, 30-month-olds (N = 64) selected that object in response to a neutral request, but were much less likely to do so in response to a label request. In Study 2, when a speaker both gazed at and pointed toward the familiar object, toddlers (N = 16) overwhelmingly selected the familiar object in response to a label request. The expectation that each object has just one label can lead children to discount some individual behavioral cues to a speaker's intent, though it can be over-ridden given a combination of pragmatic cues.
Research on the development of metamemory has focused primarily on children's understanding of the variables that influence how likely a person is to remember something. But metamemory also involves an understanding of why people occasionally misremember things. We asked 5- and 6-year-olds ( N = 38) to decide whether another child's mistakes in a memory game were due to false memories or guesses. Some of the fictitious child's mistakes were similar to material he had seen earlier and some were not. Six-year-olds, but not 5-year-olds, consistently attributed more similar than dissimilar mistakes to false memories. Understanding the link between similarity and false memories improves significantly between five and six years of age.
Do preschoolers think adults know more about everything than children? Or do they recognize that there are some things that children might know more about than adults? Three-, four-, and five-year-olds ( N = 65) were asked to decide whether an adult or child informant would better be able to answer a variety of questions about the nutritional value of foods and about toys. Children at all ages chose to direct the food questions to the adult and the toy questions to the child. Thus, there are some kinds of information for which preschoolers expect that a child would be a better informant than an adult.
When children hear an object referred to with a label that is moderately discrepant from its appearance, they frequently make inferences about that object consistent with the label rather than its appearance. We asked whether 3-year-olds actually believe these unexpected labels ("conversion"), or whether their inferences simply reflect a desire to comply with the considerable experimental demands of the induction task ("compliance"). Specifically, we asked how likely children would be to pass an unexpected label on to another person who had not been present during the labeling event. Results showed that children who used an unexpected label as the basis for inference passed that label on to another person about as often as they could remember it. This suggests that children's label-based inferences do reflect conversion rather than mere compliance.
Happiness is generally considered an emotion with only beneficial effects, particularly in childhood. However, there are some situations where the style of information processing triggered by happiness could be a liability. In particular, happiness seems to motivate a top-down processing style, which could impair performance when attention to detail is required. Indeed, in Experiment 1, 10- to 11-year-old children ( N = 30) induced to feel a happy mood were slower to locate a simple shape embedded in a complex figure than those induced to feel a sad mood. In Experiment 2, 6- to 7-year-old children ( N = 61) induced to feel a happy mood found fewer embedded shapes than those induced to feel a sad or neutral mood . Happiness may have unintended and possibly undesirable cognitive consequences, even in childhood.
Two studies investigated 3- to 5-year-olds' trust in a reliable informant when judging novel labels and novel plural and past tense forms. In Study 1, children endorsed the names of new objects given by an informant who had earlier labeled familiar objects correctly over the names given by an informant who had labeled the same objects incorrectly. In Study 2, children endorsed novel names given by an informant who had earlier expressed the plural of familiar nouns correctly over one who had expressed the plural incorrectly. But when judging the appropriateness of the plural and past tense of novel nouns and verbs, children at all ages overwhelmingly endorsed regular forms provided by the formerly unreliable labeler (Study 1) or morphologist (Study 2) rather than irregular forms provided by the formerly reliable informant.
Under most circumstances, children (and adults) can safely assume that testimony they hear is true. In two studies, we investigated whether 3-year-olds ( N = 100) would continue to hold this assumption even if the person who provided the testimony behaved in an uncertain, ignorant, and/or distracted manner. In Study 1, children were less likely to trust that, e.g., a key-like object was a spoon if the speaker indicated uncertainty about her testimony (e.g., "I think this is a spoon") than if she simply labeled the object ostensively (e.g., "This is a spoon"). In Study 2, 3-year-olds were also more skeptical about a speaker's testimony when she had earlier made an obvious naming error and seemed distracted, but not when she either made an error or seemed distracted. These results indicate that 3-year-olds can respond differently to the same testimony, depending on the speaker's behavior.
Children must be willing to accept some of what they hear "on faith," even when that testimony conflicts with their own expectations. The study reported here investigated the relationship between vocabulary size, object recognition, and 24-month-olds' ( N = 40) willingness to accept potentially surprising testimony about the category to which an object belongs. Results showed that children with larger vocabularies were better able to recognize atypical exemplars of familiar categories than children with smaller vocabularies. However, they were also most likely to accept unexpected testimony that an object that looked like a member of one familiar category was actually a member of another. These results indicate that 24-month-olds trust classifications provided by adult labeling patterns even when they conflict with the classifications children generate on their own.
A label can efficiently convey non-obvious information about category membership, but this information can sometimes conflict with one's own expectations. Two studies explored whether 24-month-olds ( N = 56) would be willing to accept a category label indicating that an animal (Study 1) or artifact (Study 2) that looked like a member of one familiar category was actually a member of a different familiar category. Results showed that children were receptive to these unexpected labels, and used them as the basis for inference. These findings indicate that linguistic information can lead even toddlers to "disbelieve their eyes."
People can monitor the accuracy of their own memories and can regulate their responses accordingly. But can they monitor and make use of another person's memory? We document a new phenomenon whereby participants neglect a partner's expertise when deciding whether to defer to that partner's memory or to rely on their own. In two experiments, participants studied images for either more, less, or the same amount of time as a partner, and on subsequent recognition tests, they were directed to maximize team performance by either answering themselves or letting their partner respond. In both experiments individuals failed to use their knowledge that the partner would probably have a better memory for certain items. Only when explicitly instructed to estimate their accuracy relative to their partner's did participants take advantage of their partner's greater expertise.
Children learn much of what they know—from words to their birthdates to the fact that the earth is round—from what other people tell them. But not everyone is an equally good informant. One way they can estimate the credibility of a speaker is by evaluating how reliable that person has been in the past. Even preschoolers prefer learning new words from an adult who has previously correctly labeled objects rather than one who has incorrectly done so (Koenig, Clement, & Harris, 2004). Children may also make predictions about a speaker based on that person's membership in a particular group. For example, 4-year-olds expect that an unfamiliar adult, but not necessarily an unfamiliar child, would know the meaning of the word hypochondriac (Taylor, Cartwright, & Bowden, 1991). Which of these two cues to a speaker's credibility—reliability or age—do 3- and 4-year-old children find more compelling?
The creator of an artifact, by virtue of having made the object, has privileged knowledge about its intended function. Do children recognize that the label an artifact's creator uses can convey this privileged information? 3- and 4-year-olds were presented with an object that looked like a member of one familiar artifact category, but which the speaker referred to with the label of a different familiar category (e.g., a key-like object was called a "spoon"). Children who heard the speaker refer to the object as something she made were more likely to assign its function on the basis of the anomalous label she used than those who heard it referred to as something the speaker found. Thus, even very young children expect a unique connection between the label the creator of an artifact uses and the function she intends it to have.
Children tend to infer that when a speaker uses a new label, the label refers to an unlabeled object rather than one they already know the label for. Does this inference reflect a default assumption that words are mutually exclusive? Or does it instead reflect the result of a pragmatic reasoning process about what the speaker intended? In two studies, we distinguish between these possibilities. Preschoolers watched as a speaker pointed toward (Study 1) or looked at (Study 2) a familiar object while requesting the referent for a new word (e.g., "Can you give me the blicket?"). In both studies, despite the speaker's unambiguous behavioral cue indicating an intent to refer to a familiar object, children inferred that the novel label referred to an unfamiliar object. These results suggest that children expect words to be mutually exclusive even when a speaker provides some kinds of pragmatic evidence to the contrary.
A label can convey non-obvious information about category membership. Three studies show that preschoolers ( N = 144) sometimes ignore or reject labels that conflict with appearance, particularly when they are uncertain that the speaker meant to use those labels. In Study 1, 4-year-olds were more reluctant than 3-year-olds to accept that, for example, a cat-like animal was a dog just on the basis of hearing it called a "dog." In Studies 2 and 3, this reluctance was overcome when the speaker explicitly or implicitly indicated that use of the unexpected labels was intentional. These studies demonstrate that preschoolers do not treat labels as atheoretical features of objects; rather, they interpret them in light of their understanding of the labeler's communicative intent.
Indirect word learning lacks many of the overt social-pragmatic cues to reference available in direct word learning, yet the two result in equally robust mappings when comprehension is assessed immediately after learning. The 3 studies reported here investigated how 3-year-olds (N = 96) respond to more challenging tests of the relative strength of indirect and direct word learning. In Study 1, children's comprehension of indirectly and directly learned proper and common names was tested after a 2-day delay. Both types of learning resulted in proper name mappings that picked out an individual, and common name mappings that could be extended to another category member. In Studies 2 and 3, children's comprehension was tested after they had been provided with additional, and sometimes inconsistent, information about the scope of previously learned words. There was a hint of a difference between indirect and direct word learning, but results overall suggested that the two were equivalent.
A single, indirect exposure to a novel word provides information that could be used to make a fast mapping between the word and its referent, but it is not known how well this initial mapping specifies the function of the new word. The 4 studies reported here compare the fast mapping of new proper and common names following an indirect exposure requiring inference with the learning of new names following ostension. In Study 1, 3-year-olds were shown an animate-inanimate pair of objects and asked to select, e.g., Dax, a dax, or one. Children spontaneously selected an animate over an inanimate object as the referent for a novel proper name, but had no animacy preference in common name or baseline conditions. Next, the children were asked to perform actions on, e.g., Dax or a dax, when presented with an array of 3 objects: the one they just selected, another member of like kind, and a distracter. An indirectly learned proper name was treated as a marker for the originally selected object only, while a new common name was generalized to include the other category member. Study 2 showed that mappings made by inference were as robust as those made by ostension. Studies 3 and 4 demonstrated that even 2-year-olds can learn as much about the function of a new word from an indirect exposure as from ostension.
Terrace, H. S., Chen, S., & Jaswal, V. (1996). Recall of three-item sequences by pigeons. Animal Learning and Behavior, 24, 193-205. [Abstract]
Eight male pigeons were trained to recall an arbitrary sequence on a delayed matching-to-successive-samples (DMSSs) task. Sample items were presented successively and then displayed simultaneously. Ss were required to respond to items in the order in which they appeared. In Exp 1, Ss responded correctly on 75% of the trials on a 2-item DMSSs task but at a chance level of accuracy on a 3-item task. In Exp 2, Ss who learned to produce a 3-item sequence prior to DMSSs training mastered a 3-item DMSSs task at a 75% level of accuracy. Control Ss, trained initially with the same items on nonserial tasks, performed as poorly on a 3-item DMSSs task as the naive Ss of Exp 1. It was hypothesized that Ss that first learned to produce a 3-item list were able to recall 3-item samples in DMSSs because they had learned to represent 3-item sequences.
Jaswal, V. K., & Pérez-Edgar, K. (2014). Resolving conflicts between observation and testimony: The role of inhibitory control. In E. J. Robinson & S. Einav (Eds.), Trust and skepticism: Children's selective learning from testimony (pp. 110-122). New York: Psychology Press.
Jaswal, V. K. (2013). Biased to believe. In M. R. Banaji & S. A. Gelman (Eds.), Navigating the social world: What infants, children, and other species can teach us (pp. 241-244). New York: Oxford University Press.
McKercher, D. A., & Jaswal, V. K.(2011). Using judgment tasks to assess language knowledge. In E. Hoff (Ed.), The Blackwell guide to research methods in child language (pp. 149-161). NY: Wiley-Blackwell.
Jaswal, V. K. (2010). Division of linguistic labor. In P. Hogan (Ed.), The Cambridge encyclopedia of the language sciences (p. 270). Cambridge, England: Cambridge University Press.
DeLoache, J. S., Ganea, P. A., & Jaswal, V. K. (2009). Early learning through language. In J. Colombo, P. McCardle, & L. Freund (Eds.), Infant pathways to language: Methods, models, and research disorders (pp. 119-140). New York: Psychology Press.
Jaswal, V. K., & Fernald, A. (2007). Learning to communicate. In M. Lewis & A. Slater (Eds.), Introduction to infant development, 2nd Edition (pp. 270-287). Oxford: Oxford University Press.
Markman, E. M., & Jaswal, V. K. (2004). Acquiring and using a grammatical form class: Lessons from the proper-count distinction. In D. G. Hall & S. Waxman (Eds.), Weaving a lexicon (pp. 371-409). Cambridge, MA: MIT Press. [pdf]
Markman, E. M., & Jaswal, V. K. (2003). Abilities and assumptions underlying conceptual development. In D. H. Rakison & L. M. Oakes (Eds.), Early category and concept development: Making sense of the blooming, buzzing confusion (pp. 384-402). Oxford: Oxford University Press. [pdf]
Jaswal, V. K., & Fernald, A. (2002). Learning to communicate. In M. Lewis & A. Slater (Eds.), Introduction to infant development (pp. 244-265). Oxford: Oxford University Press. [pdf]
Jaswal, V. K., & Markman, E. M. (2002). Children’s acceptance and use of unexpected category labels to draw non-obvious inferences. In W. Gray & C. Schunn (Eds.), Proceedings of the twenty-fourth annual conference of the Cognitive Science Society (pp. 500-505). Hillsdale, NJ: Erlbaum. [pdf]
Writings for the Popular Press
Jaswal, V. K. (2014). With gifts, size may not matter. Op-ed, Richmond Times-Dispatch, 2/9/14.[Read Article]
Jaswal, V. K. (2010). When do children develop skepticism? Big Questions Online, 10/28/10.[Read Article]
Drell, M. B. & Jaswal, V. K. (2013). Say sorry: Making amends following an accidental transgression. Biennial meeting of the Cognitive Development Society, Memphis TN. [pdf]
Rowell, S. R. & Jaswal, V. K. (2013). Strategic memory monitoring: The role of confidence in help seeking. Biennial meeting of the Cognitive Development Society, Memphis TN. [pdf]
Drell, M. B., Kondrad, R. L., & Jaswal, V. K. (2013). "At least she said something": Children prefer inaccurate over ignorant informants. Biennial meeting of the Society for Research in Child Development, Seattle WA. [pdf]
Rowell, S.R. & Jaswal, V. K. (2013). Seeing vs. hearing: Comparing information acquired directly with information acquired via testimony. Biennial meeting of the Society for Research in Child Development, Seattle WA. [pdf]