Bio


I am broadly interested in the human ability to reason about others, learn from others, and inform others in communicative contexts. How do we construct rich, abstract theories about how the world works from our everyday experiences that often involve other people, and how do we communicate what we know to others? My research brings together various approaches -- primarily developmental, computational, and neuroimaging methods -- aiming to provide a unified description of the cognitive and neural mechanisms that underlie the representations and inferential processes that allow us to learn about the world, and to communicate what we know.

Academic Appointments


Program Affiliations


  • Symbolic Systems Program

Professional Education


  • Ph.D., MIT, Cognitive Science (2012)

2020-21 Courses


All Publications


  • Young children consider the expected utility of others' learning to decide what to teach. Nature human behaviour Bridgers, S., Jara-Ettinger, J., Gweon, H. 2019

    Abstract

    Direct instruction facilitates learning without the costs of exploration, yet teachers must be selective because not everything can nor needs to be taught. How do we decide what to teach and what to leave for learners to discover? Here we investigate the cognitive underpinnings of the human ability to prioritize what to teach. We present a computational model that decides what to teach by maximizing the learner's expected utility of learning from instruction and from exploration, and we show that children (aged 5-7years) make decisions that are consistent with the model's predictions (that is, minimizing the learner's costs and maximizing the rewards). Children flexibly considered either the learner's utility or their own, depending on the context, and even considered costs they had not personally experienced, to decide what to teach. These results suggest that utility-based reasoning may play an important role in curating cultural knowledge by supporting selective transmission of high-utility information.

    View details for DOI 10.1038/s41562-019-0748-6

    View details for PubMedID 31611659

  • Integrating Expectations and Outcomes: Preschoolers' Developing Ability to Reason About Others' Emotions DEVELOPMENTAL PSYCHOLOGY Asaba, M., Ong, D. C., Gweon, H. 2019; 55 (8): 1680–93

    Abstract

    People's emotional experiences depend not only on what actually happened, but also on what they thought would happen. However, these expectations about future outcomes are not always communicated explicitly. Thus, the ability to infer others' expectations in context and understand how these expectations influence others' emotions is an important aspect of our social intelligence. Prior work suggests that an abstract understanding of how expectations modulate emotional responses may not emerge until 7 to 8 years of age. Using a novel paradigm that capitalizes on intuitive physics to generate contextually plausible expectations, we present evidence for expectation-based emotion inference in preschool-aged children. Given two bowlers who experienced identical final outcomes (hitting 3 of 6 pins), we varied the trajectory of their balls such that one would initially expect to hit all pins (high-expectation), while the other would expect to hit none (low-expectation). In Experiment 1, both 4- and 5-year-olds appropriately adjusted characters' happiness ratings upward (low-expectation) or downward (high-expectation) relative to their initial emotions; however, only 5-year-olds made adjustments robust enough to manifest as higher final ratings for the low-expectation than the high-expectation character. In Experiments 2-3, we replicate these results and show that 5-year-olds reliably differentiate the characters' emotions even when their expectations must be inferred from context. An internal meta-analysis revealed a robust and consistent effect across the three experiments. Together, these findings provide the earliest evidence for expectation-based emotion reasoning and suggest that the ability to spontaneously generate and consider others' expectations continues to develop during preschool years. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

    View details for DOI 10.1037/dev0000749

    View details for Web of Science ID 000476498000010

    View details for PubMedID 31094560

  • The rare preference effect: Statistical information influences social affiliation judgments. Cognition Velez, N., Bridgers, S., Gweon, H. 2019; 192: 103994

    Abstract

    Shared preferences-liking the same things-facilitate and strengthen bonds between individuals. However, not all shared preferences are equally meaningful; sharing a rare preference with someone is often more exciting and meaningful than sharing a common preference. Here we present evidence for the rare preference effect: Participants chose to interact with (Experiment 1), and endorsed interactions between (Experiment 2), individuals who shared a rare preference, rather than those who shared a common preference, and this tendency increased with the relative rarity of the preference. While having a preference usually implies knowing and liking something, the presence of shared knowledge alone was sufficient to give rise to the rare preference effect (Experiments 3 & 4). Further, we find that social affiliation judgments are modulated by the causal process by which individuals came to have shared knowledge: Participants preferred to interact with someone who acquired a shared preference deliberately rather than accidentally (Experiment 5). In addition to the many cultural and emotional factors that drive mutual attraction, these results suggest that people's decisions about with whom to interact are systematically influenced by the statistics of the social environment.

    View details for DOI 10.1016/j.cognition.2019.06.006

    View details for PubMedID 31229739

  • Integrating Incomplete Information With Imperfect Advice TOPICS IN COGNITIVE SCIENCE Velez, N., Gweon, H. 2019; 11 (2): 299–315

    View details for DOI 10.1111/tops.12388

    View details for Web of Science ID 000467986500003

  • Response patterns in the developing social brain are organized by social and emotion features and disrupted in children diagnosed with autism spectrum disorder. Cortex; a journal devoted to the study of the nervous system and behavior Richardson, H., Gweon, H., Dodell-Feder, D., Malloy, C., Pelton, H., Keil, B., Kanwisher, N., Saxe, R. 2019; 125: 12–29

    Abstract

    Adults and children recruit a specific network of brain regions when engaged in "Theory of Mind" (ToM) reasoning. Recently, fMRI studies of adults have used multivariate analyses to provide a deeper characterization of responses in these regions. These analyses characterize representational distinctions within the social domain, rather than comparing responses across preferred (social) and non-preferred stimuli. Here, we conducted opportunistic multivariate analyses in two previously collected datasets (Experiment 1: n = 20 5-11 year old children and n = 37 adults; Experiment 2: n = 76 neurotypical and n = 29 5-12 year old children diagnosed with Autism Spectrum Disorder (ASD)) in order to characterize the structure of representations in the developing social brain, and in order to discover if this structure is disrupted in ASD. Children listened to stories that described characters' mental states (Mental), non-mentalistic social information (Social), and causal events in the environment (Physical), while undergoing fMRI. We measured the extent to which neural responses in ToM brain regions were organized according to two ToM-relevant models: 1) a condition model, which reflected the experimenter-generated condition labels, and 2) a data-driven emotion model, which organized stimuli according to their emotion content. We additionally constructed two control models based on linguistic and narrative features of the stories. In both experiments, the two ToM-relevant models outperformed the control models. The fit of the condition model increased with age in neurotypical children. Moreover, the fit of the condition model to neural response patterns was reduced in the RTPJ in children diagnosed with ASD. These results provide a first glimpse into the conceptual structure of information in ToM brain regions in childhood, and suggest that there are real, stable features that predict responses in these regions in children. Multivariate analyses are a promising approach for sensitively measuring conceptual and neural developmental change and individual differences in ToM.

    View details for DOI 10.1016/j.cortex.2019.11.021

    View details for PubMedID 31958654

  • Integrating Incomplete Information With Imperfect Advice. Topics in cognitive science Velez, N., Gweon, H. 2018

    Abstract

    When our own knowledge is limited, we often turn to others for information. However, social learning does not guarantee accurate learning or better decisions: Other people's knowledge can be as limited as our own, and their advice is not always helpful. This study examines how human learners put two "imperfect" heads together to make utility-maximizing decisions. Participants played a card game where they chose to "stay" with a card of known value or "switch" to an unknown card, given an advisor's advice to stay or switch. Participants used advice strategically based on which cards the advisor could see (Experiment 1), how helpful the advisor was (Experiment 2), and what strategy the advisor used to select advice (Experiment 3). Overall, participants benefited even from imperfect advice based on incomplete information. Participants' responses were consistent with a Bayesian model that jointly infers how the advisor selects advice and the value of the advisor's card, compared to an alternative model that weights advice based on the advisor's accuracy. By reasoning about others' minds, human learners can make the best of even noisy, impoverished social information.

    View details for PubMedID 30414253

  • Development of Children's Sensitivity to Overinformativeness in Learning and Teaching DEVELOPMENTAL PSYCHOLOGY Gweon, H., Shafto, P., Schulz, L. 2018; 54 (11): 2113–25

    Abstract

    Effective communication requires knowing the "right" amount of information to provide; what is necessary for a naïve learner to arrive at a target hypothesis may be superfluous and inefficient for a knowledgeable learner. The current study examines 4- to 7-year-olds' developing sensitivity to overinformative communication and their ability to decide how much information is appropriate depending on the learner's prior knowledge. In Experiment 1 (N = 184, age = 4.09-7.98 years), 5- to 7-year-old children preferred teachers who gave costly, exhaustive demonstrations when learners were naïve, but preferred teachers who gave efficient, selective demonstrations when learners were already knowledgeable given their prior experience (i.e., common ground). However, 4-year-olds did not show a clear preference. In Experiment 2 (N = 80, age = 4.05-6.99 years), we asked whether children flexibly modulated their own teaching based on learners' knowledge. Five and 6-year-olds, but not 4-year-olds, were more likely to provide exhaustive demonstrations to naïve learners than to knowledgeable learners. These results suggest that by 5 years of age, children are sensitive to overinformativeness and understand the trade-off between informativeness and efficiency; they reason about what others know based on the presence or absence of common ground and flexibly decide how much information is appropriate both as learners and as teachers. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

    View details for DOI 10.1037/dev0000580

    View details for Web of Science ID 000448187100010

    View details for PubMedID 30265027

  • Means-Inference as a Source of Variability in Early Helping FRONTIERS IN PSYCHOLOGY Bridgers, S., Gweon, H. 2018; 9
  • From Exploration to Instruction: Children Learn From Exploration and Tailor Their Demonstrations to Observers' Goals and Competence. Child development Gweon, H., Schulz, L. 2018

    Abstract

    This study investigated whether children learn from exploration and act as effective informants by providing informative demonstrations tailored to observers' goals and competence. Children (4.0-6.9years, N=98) explored a causally ambiguous toy to discover its causal structure and then demonstrated the toy to a naive observer. Children provided more costly and informative evidence when the observer wanted to learn about the toy than observe its effects (Experiment 1) and when the observer was ordinary than exceptionally intelligent (Experiment 2). Relative to the evidence they generated during exploration, children produced fewer, less costly actions when the observer wanted or needed less evidence. Children understand the difference between acting-to-learn and acting-to-inform; after learning from exploration, they consider others' goals and competence to provide "uninstructed instruction".

    View details for PubMedID 29635785

  • Means-Inference as a Source of Variability in Early Helping. Frontiers in psychology Bridgers, S., Gweon, H. 2018; 9: 1735

    Abstract

    Humans, as compared to their primate relatives, readily act on behalf of others: we help, inform, share resources with, and provide emotional comfort for others. Although these prosocial behaviors emerge early in life, some types of prosocial behaviors seem to emerge earlier than others, and some tasks elicit more reliable helping than others. Here we discuss existing perspectives on the sources of variability in early prosocial behaviors with a particular focus on the variability within the domain of instrumental helping. We suggest that successful helping behavior not only requires an understanding of others' goals (goal-inference), but also the ability to figure out how to help (means-inference). We review recent work that highlights two key factors that support means-inference: causal reasoning and sensitivity to the expected costs and rewards of actions. Once we begin to look closely at the process of deciding how to help someone, even a seemingly simple helping behavior is, in fact, a consequence of a sophisticated decision-making process; it involves reasoning about others (e.g., goals, actions, and beliefs), about the causal structure of the physical world, and about one's own ability to provide effective help. A finer-grained understanding of the role of these inferences may help explain the developmental trajectory of prosocial behaviors in early childhood. We discuss the promise of computational models that formalize this decision process and how this approach can provide additional insights into why humans show unparalleled propensity and flexibility in their ability to help others.

    View details for PubMedID 30319483

    View details for PubMedCentralID PMC6168682

  • 'To the victor go the spoils': Infants expect resources to align with dominance structures. Cognition Enright, E. A., Gweon, H., Sommerville, J. A. 2017; 164: 8-21

    Abstract

    Previous research has found that within the first year of life infants possess rich knowledge about social structures (i.e., that some individuals are dominant over other individuals) as well as expectations about resource distributions (i.e., that resources are typically distributed equally to recipients). We investigated whether infants' expectations about resource distribution can be modulated by information about the dominance structure between the recipients. We first replicated the finding that infants attribute a stable dominance hierarchy to a pair of individuals when their goals conflicted and one individual yielded to the other (Expt. 1), and that this sensitivity is not driven by lower-level perceptual factors (Expt. 2). In Experiments 3-5, we tested our main hypothesis that infants' attention to equal and unequal distributions varies as a function of prior social dominance information. We first replicated and extended prior work by establishing that infants looked significantly longer to unequal than equal resource distributions when no prior information about dominance was provided about recipients (Expt. 3). Critically, following social dominance information, infants looked significantly longer to an equal distribution of resources than a distribution that favored the dominant individual (Expt. 4), and looked significantly longer when the submissive individual received more resources compared to when the dominant individual received more resources (Expts. 4 and 5). Together, these findings suggest that infants expect resources to align with social dominance structures.

    View details for DOI 10.1016/j.cognition.2017.03.008

    View details for PubMedID 28346870

  • Order Matters: Children's Evaluation of Underinformative Teachers Depends on Context. Child development Gweon, H., Asaba, M. 2017

    Abstract

    The ability to evaluate "sins of omission"-true but pragmatically misleading, underinformative pedagogy-is critical for learning. This study reveals a developmental change in children's evaluation of underinformative teachers and investigates the nature of their limitations. Participants rated a fully informative teacher and an underinformative teacher in two different orders. Six- and 7-year-olds (N = 28) successfully distinguished the teachers regardless of the order (Experiment 1), whereas 4- and 5-year-olds (N = 82) succeeded only when the fully informative teacher came first (Experiments 2 and 3). After seeing both teachers, 4-year-olds (N = 32) successfully preferred the fully informative teacher (Experiment 4). These results are discussed in light of developmental work in pragmatic implicature, suggesting that young children might struggle with spontaneously generating relevant alternatives for evaluating underinformative pedagogy.

    View details for DOI 10.1111/cdev.12825

    View details for PubMedID 28542838

  • Learning the Structure of Social Influence COGNITIVE SCIENCE Gershman, S. J., Pouncy, H. T., Gweon, H. 2017; 41: 545-575

    Abstract

    We routinely observe others' choices and use them to guide our own. Whose choices influence us more, and why? Prior work has focused on the effect of perceived similarity between two individuals (self and others), such as the degree of overlap in past choices or explicitly recognizable group affiliations. In the real world, however, any dyadic relationship is part of a more complex social structure involving multiple social groups that are not directly observable. Here we suggest that human learners go beyond dyadic similarities in choice behaviors or explicit group memberships; they infer the structure of social influence by grouping individuals (including themselves) based on choices, and they use these groups to decide whose choices to follow. We propose a computational model that formalizes this idea, and we test the model predictions in a series of behavioral experiments. In Experiment 1, we reproduce a well-established finding that people's choices are more likely to be influenced by someone whose past choices are more similar to their own past choices, as predicted by our model as well as dyadic similarity models. In Experiments 2-5, we test a set of unique predictions of our model by looking at cases where the degree of choice overlap between individuals is equated, but their choices indicate a latent group structure. We then apply our model to prior empirical results on infants' understanding of others' preferences, presenting an alternative account of developmental changes. Finally, we discuss how our model relates to classical findings in the social influence literature and the theoretical implications of our model. Taken together, our findings demonstrate that structure learning is a powerful framework for explaining the influence of social information on decision making in a variety of contexts.

    View details for DOI 10.1111/cogs.12480

    View details for Web of Science ID 000399736400008

    View details for PubMedID 28294384

  • The Naïve Utility Calculus: Computational Principles Underlying Commonsense Psychology. Trends in cognitive sciences Jara-Ettinger, J., Gweon, H., Schulz, L. E., Tenenbaum, J. B. 2016; 20 (8): 589-604

    Abstract

    We propose that human social cognition is structured around a basic understanding of ourselves and others as intuitive utility maximizers: from a young age, humans implicitly assume that agents choose goals and actions to maximize the rewards they expect to obtain relative to the costs they expect to incur. This 'naïve utility calculus' allows both children and adults observe the behavior of others and infer their beliefs and desires, their longer-term knowledge and preferences, and even their character: who is knowledgeable or competent, who is praiseworthy or blameworthy, who is friendly, indifferent, or an enemy. We review studies providing support for the naïve utility calculus, and we show how it captures much of the rich social reasoning humans engage in from infancy.

    View details for DOI 10.1016/j.tics.2016.05.011

    View details for PubMedID 27388875

  • Learning From Others and Spontaneous Exploration: A Cross-Cultural Investigation CHILD DEVELOPMENT Shneidman, L., Gweon, H., Schulz, L. E., Woodward, A. L. 2016; 87 (3): 723-735

    Abstract

    How does early social experience affect children's inferences and exploration? Following prior work on children's reasoning in pedagogical contexts, this study examined U.S. children with less experience in formal schooling and Yucatec Mayan children whose early social input is predominantly observational. In Experiment 1, U.S. 2-year-olds (n = 77) showed more restricted exploration of a toy following a pedagogical demonstration than an interrupted, accidental, or no demonstration (baseline). In Experiment 2, Yucatec Mayan and U.S. 2-year-olds (n = 66) showed more restricted exploration following a pedagogical than an observational demonstration, while only Mayan children showed more restriction with age. These results suggest that although schooling is not a necessary precursor for sensitivity to pedagogy, early social experience may influence children's inferences and exploration in pedagogical contexts.

    View details for DOI 10.1111/cdev.12502

    View details for Web of Science ID 000379913500009

    View details for PubMedID 27189400

  • Children's understanding of the costs and rewards underlying rational action COGNITION Jara-Ettinger, J., Gweon, H., Tenenbaum, J. B., Schulz, L. E. 2015; 140: 14-23

    Abstract

    Humans explain and predict other agents' behavior using mental state concepts, such as beliefs and desires. Computational and developmental evidence suggest that such inferences are enabled by a principle of rational action: the expectation that agents act efficiently, within situational constraints, to achieve their goals. Here we propose that the expectation of rational action is instantiated by a naïve utility calculus sensitive to both agent-constant and agent-specific aspects of costs and rewards associated with actions. In four experiments, we show that, given an agent's choices, children (range: 5-6 year olds; N=96) can infer unobservable aspects of costs (differences in agents' competence) from information about subjective differences in rewards (differences in agents' preferences) and vice versa. Moreover, children can design informative experiments on both objects and agents to infer unobservable constraints on agents' actions.

    View details for DOI 10.1016/j.cognition.2015.03.006

    View details for Web of Science ID 000355042100002

    View details for PubMedID 25867996

  • Sins of omission: Children selectively explore when teachers are under-informative COGNITION Gweon, H., Pelton, H., Konopka, J. A., Schulz, L. E. 2014; 132 (3): 335-341

    Abstract

    Do children know when people tell the truth but not the whole truth? Here we show that children accurately evaluate informants who omit information and adjust their exploratory behavior to compensate for under-informative pedagogy. Experiment 1 shows that given identical demonstrations of a toy, children (6- and 7-year-olds) rate an informant lower if the toy also had non-demonstrated functions. Experiment 2 shows that given identical demonstrations, six-year-olds explore a toy more broadly if the informant previously committed a sin of omission. These results suggest that children consider both accuracy and informativeness in evaluating others' credibility and adjust their exploratory behavior to compensate for under-informative testimony when an informant's credibility is in doubt.

    View details for DOI 10.1016/j.cognition.2014.04.013

    View details for Web of Science ID 000340013900009

    View details for PubMedID 24873737

  • Differences in the right inferior longitudinal fasciculus but no general disruption of white matter tracts in children with autism spectrum disorder PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Koldewyn, K., Yendiki, A., Weigelt, S., Gweon, H., Julian, J., Richardson, H., Malloy, C., Saxe, R., Fischl, B., Kanwisher, N. 2014; 111 (5): 1981-1986

    Abstract

    One of the most widely cited features of the neural phenotype of autism is reduced "integrity" of long-range white matter tracts, a claim based primarily on diffusion imaging studies. However, many prior studies have small sample sizes and/or fail to address differences in data quality between those with autism spectrum disorder (ASD) and typical participants, and there is little consensus on which tracts are affected. To overcome these problems, we scanned a large sample of children with autism (n = 52) and typically developing children (n = 73). Data quality was variable, and worse in the ASD group, with some scans unusable because of head motion artifacts. When we follow standard data analysis practices (i.e., without matching head motion between groups), we replicate the finding of lower fractional anisotropy (FA) in multiple white matter tracts. However, when we carefully match data quality between groups, all these effects disappear except in one tract, the right inferior longitudinal fasciculus (ILF). Additional analyses showed the expected developmental increases in the FA of fiber tracts within ASD and typical groups individually, demonstrating that we had sufficient statistical power to detect known group differences. Our data challenge the widely claimed general disruption of white matter tracts in autism, instead implicating only one tract, the right ILF, in the ASD phenotype.

    View details for DOI 10.1073/pnas.1324037111

    View details for Web of Science ID 000330587600075

    View details for PubMedID 24449864

    View details for PubMedCentralID PMC3918797

  • Theory of Mind Performance in Children Correlates With Functional Specialization of a Brain Region for Thinking About Thoughts CHILD DEVELOPMENT Gweon, H., Dodell-Feder, D., Bedny, M., Saxe, R. 2012; 83 (6): 1853-1868

    Abstract

    Thinking about other people's thoughts recruits a specific group of brain regions, including the temporo-parietal junctions (TPJ), precuneus (PC), and medial prefrontal cortex (MPFC). The same brain regions were recruited when children (N=20, 5-11 years) and adults (N=8) listened to descriptions of characters' mental states, compared to descriptions of physical events. Between ages 5 and 11 years, responses in the bilateral TPJ became increasingly specific to stories describing mental states as opposed to people's appearance and social relationships. Functional activity in the right TPJ was related to children's performance on a high level theory of mind task. These findings provide insights into the origin of neural mechanisms of theory of mind, and how behavioral and neural changes can be related in development.

    View details for DOI 10.1111/j.1467-8624.2012.01829.x

    View details for Web of Science ID 000314111900002

    View details for PubMedID 22849953

  • The double-edged sword of pedagogy: Instruction limits spontaneous exploration and discovery COGNITION Bonawitz, E., Shafto, P., Gweon, H., Goodman, N. D., Spelke, E., Schulz, L. 2011; 120 (3): 322-330

    Abstract

    Motivated by computational analyses, we look at how teaching affects exploration and discovery. In Experiment 1, we investigated children's exploratory play after an adult pedagogically demonstrated a function of a toy, after an interrupted pedagogical demonstration, after a naïve adult demonstrated the function, and at baseline. Preschoolers in the pedagogical condition focused almost exclusively on the target function; by contrast, children in the other conditions explored broadly. In Experiment 2, we show that children restrict their exploration both after direct instruction to themselves and after overhearing direct instruction given to another child; they do not show this constraint after observing direct instruction given to an adult or after observing a non-pedagogical intentional action. We discuss these findings as the result of rational inductive biases. In pedagogical contexts, a teacher's failure to provide evidence for additional functions provides evidence for their absence; such contexts generalize from child to child (because children are likely to have comparable states of knowledge) but not from adult to child. Thus, pedagogy promotes efficient learning but at a cost: children are less likely to perform potentially irrelevant actions but also less likely to discover novel information.

    View details for DOI 10.1016/j.cognition.2010.10.001

    View details for Web of Science ID 000293312400003

    View details for PubMedID 21216395

  • 16-Month-Olds Rationally Infer Causes of Failed Actions SCIENCE Gweon, H., Schulz, L. 2011; 332 (6037): 1524-1524

    Abstract

    Sixteen-month-old infants (N = 83) rationally used sparse data about the distribution of outcomes among agents and objects to solve a fundamental inference problem: deciding whether event outcomes are due to themselves or the world. When infants experienced failed outcomes, their causal attributions affected whether they sought help or explored.

    View details for DOI 10.1126/science.1204493

    View details for Web of Science ID 000291990000035

    View details for PubMedID 21700866

  • Infants consider both the sample and the sampling process in inductive generalization PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Gweon, H., Tenenbaum, J. B., Schulz, L. E. 2010; 107 (20): 9066-9071

    Abstract

    The ability to make inductive inferences from sparse data is a critical aspect of human learning. However, the properties observed in a sample of evidence depend not only on the true extension of those properties but also on the process by which evidence is sampled. Because neither the property extension nor the sampling process is directly observable, the learner's ability to make accurate generalizations depends on what is known or can be inferred about both variables. In particular, different inferences are licensed if samples are drawn randomly from the whole population (weak sampling) than if they are drawn only from the property's extension (strong sampling). Given a few positive examples of a concept, only strong sampling supports flexible inferences about how far to generalize as a function of the size and composition of the sample. Here we present a Bayesian model of the joint dependence between observed evidence, the sampling process, and the property extension and test the model behaviorally with human infants (mean age: 15 months). Across five experiments, we show that in the absence of behavioral cues to the sampling process, infants make inferences consistent with the use of strong sampling; given explicit cues to weak or strong sampling, they constrain their inferences accordingly. Finally, consistent with quantitative predictions of the model, we provide suggestive evidence that infants' inferences are graded with respect to the strength of the evidence they observe.

    View details for DOI 10.1073/pnas.1003095107

    View details for Web of Science ID 000277822600011

    View details for PubMedID 20435914

    View details for PubMedCentralID PMC2889113