Joshua Knobe

When solving problems, like making predictions or choices, people often “sample” possibilities into mind. Here, we consider whether there is structure to the kinds of thoughts people sample by default—that is, without an explicit goal. Across three experiments we found that what comes to mind by default are samples from a probability distribution that combines what people think is likely and what they think is good. Experiment 1 found that the first quantities that come to mind for everyday behaviors and events are quantities that combine what is average and ideal. Experiment 2 found, in a manipulated context, that the distribution of numbers that come to mind resemble the mathematical product of the presented statistical distribution and a (softmax-transformed) prescriptive distribution. Experiment 3 replicated these findings in a visual domain. These results provide insight into the process generating people’s conscious thoughts and invite new questions about the value of thinking about things that are both likely and good.

Within the existing metaphilosophical literature on experimental philosophy, a great deal of attention has been devoted to the claim that there are large differences in philosophical intuitions between people of different demographic groups. Some philosophers argue that this claim has important metaphilosophical implications; others argue that it does not. However, the actual empirical work within experimental philosophy seems to point to a very different sort of metaphilosophical question. Specifically, what the actual empirical work suggests is that intuitions are surprisingly robust across demographic groups. Prior to empirical study, it seemed plausible that unexpected patterns of intuition found in one demographic group would not emerge in other demographic groups. Yet, again and again, empirical work obtains the opposite result: that unexpected patterns found in one demographic group actually emerge also in other demographic groups. I cite 30 studies that find this sort of robustness. I then argue that to the extent that metaphilosophical work is to engage with the actual findings from experimental philosophy, it needs to explore the implications of the surprising robustness of philosophical intuitions across demographic differences.

Our goal in this paper is to articulate a novel account of the ordinary concept ART. At the core of our account is the idea that a puzzle surrounding our thought and talk about art is best understood as just one instance of a far broader phenomenon. In particular, we claim that one can make progress on this puzzle by drawing on research from cognitive science on dual character concepts. Thus, we suggest that the very same sort of phenomenon that is associated with ART can also be found in a broad class of other dual character concepts, including SCIENTIST, CHRISTIAN, GANGSTER, and many others. Instead of focusing narrowly on the case of ART, we try to offer a more general account of these concepts and the puzzles to which they give rise. Then, drawing on the general theory, we introduce a series of hypotheses about art concepts, and put those hypotheses to the test in three experimental studies.

Responding to recent concerns about the reliability of the published literature in psychology and other disciplines, we formed the X-Phi Replicability Project to estimate the reproducibility of experimental philosophy. Drawing on a representative sample of 40 x-phi studies published between 2003 and 2015, we enlisted 20 research teams across 8 countries to conduct a high-quality replication of each study in order to compare the results to the original published findings. We found that x-phi studies – as represented in our sample – successfully replicated about 70% of the time. We discuss possible reasons for this relatively high replication rate in the field of experimental philosophy and offer suggestions for best research practices going forward.

The concept of acting intentionally is an important nexus where ‘theory of mind’ and moral judgment meet. Preschool children’s judgments of intentional action show a valence-driven asymmetry. Children say that a foreseen but disavowed side-effect is brought about 'on purpose' when the side-effect itself is morally bad but not when it is morally good. This is the first demonstration in preschoolers that moral judgment influences judgments of ‘on-purpose’ (as opposed to purpose influencing moral judgment). Judgments of intentional action are usually assumed to be purely factual. That these judgments are sometimes partly normative — even in preschoolers — challenges current understanding. Young children’s judgments regarding foreseen side-effects depend upon whether the children process the idea that the character does not care about the side-effect. As soon as preschoolers effectively process the ‘theory of mind’ concept, NOT CARE THAT P, children show the side-effect effect.idea..

A long series of studies in social psychology have shown that the explanations people give for their own behaviors are fundamentally different from the explanations they give for the behaviors of others. Still, a great deal of uncertainty remains about precisely what sorts of differences one finds here. We offer a new approach to addressing the problem. Specifically, we distinguish between two levels of representation ─ the level of linguistic structure (which consists of the actual series of words used in the explanation) and the level of conceptual structure (which consists of the concepts these words are used to express). We then formulate and test hypotheses both about self-other differences in conceptual structure and about self-other differences in the mapping from conceptual structure to linguistic structure.

It has often been suggested that people’s ordinary folk understanding of morality involves a rejection of moral relativism and a belief in objective moral truths. The results of six studies call this claim into question. Participants did offer apparently objectivist intuitions when confronted with questions about individuals from their own culture, but they offered increasingly relativist intuitions as they were confronted with questions about individuals from increasingly different cultures or ways of life. In light of these data, the authors hypothesize that people do not have a fixed commitment to moral objectivism but instead tend to adopt different views depending on the degree to which they consider radically different perspectives on moral questions. [NOTE: This is a reprint of Sarkissian et al 2011]

When speakers utter conflicting moral sentences, it seems clear that they disagree. It has often been suggested that the fact that the speakers disagree gives us evidence for a claim about the semantics of the sentences they are uttering. Specifically, it has been suggested that the existence of the disagreement gives us reason to infer that there must be an incompatibility between the contents of these sentences. This inference then plays a key role in a now-standard argument against certain theories in moral semantics. In this paper, we introduce new evidence that bears on this debate. We show that there are moral conflict cases in which people are inclined to say both that the two speakers disagree and that it is not the case at least one of them must be saying something incorrect. We then explore how we might understand such disagreements. As a proof of concept, we sketch an account of the concept of disagreement and an independently motivated theory of moral semantics which, together, explain the possibility of such cases.

An extensive body of research suggests that the distinction between doing and allowing plays a critical role in shaping moral appraisals. Here, we report evidence from a pair of experiments suggesting that the converse is also true: moral appraisals affect doing/allowing judgments. Specifically, morally bad behavior is more likely to be construed as actively ‘doing’ than as passively ‘allowing’. This finding adds to a growing list of folk concepts influenced by moral appraisal, including causation and intentional action. We therefore suggest that the present finding favors the view that moral appraisal plays a pervasive role in shaping diverse cognitive representations across multiple domains.

People often engage in “offline simulation”, considering what would happen if they performed certain actions in the future, or had performed different actions in the past. Prior research shows that these simulations are biased towards actions a person considers to be good—i.e., likely to pay off. We ask whether, and why, this bias might be adaptive. Through computational experiments we compare five agents who differ only in the way they engage in offline simulation, across a variety of different environment types. Broadly speaking, our experiments reveal that simulating actions one already regards as good does in fact confer an advantage in downstream decision making, although this general pattern interacts with features of the environment in important ways. We contrast this bias with alternatives such as simulating actions whose outcomes are instead uncertain.

The Twin Earth thought experiment invites us to consider a liquid that has all of the superficial properties associated with water (clear, potable, etc.) but has entirely different deeper causal properties (composed of “XYZ” rather than of H2O). Although this thought experiment was originally introduced to illuminate questions in the theory of reference, it has also played a crucial role in empirically informed debates within the philosophy of psychology about people’s ordinary natural kind concepts. Those debates have sought to accommodate an apparent fact about ordinary people’s judgments: Intuitively, the Twin Earth liquid is not water. We present results from four experiments showing that people do not, in fact, have this intuition. Instead, people tend to have the intuition that there is a sense in which the liquid is not water but also a sense in which it is water. We explore the implications of this finding for debates about theories of natural kind concepts, arguing that it supports views positing two distinct criteria for membership in natural kind categories – one based on deeper causal properties, the other based on superficial, observable properties.

When agents violate norms, they are typically judged to be more of a cause of resulting outcomes. In this paper, we suggest that norm violations also affect the causality attributed to other agents, a phenomenon we refer to as "causal superseding." We propose and test a counterfactual reasoning model of this phenomenon in four experiments. Experiments 1 and 2 provide an initial demonstration of the causal superseding effect and distinguish it from previously studied effects. Experiment 3 shows that this causal superseding effect is dependent on a particular event structure, following a prediction of our counterfactual model. Experiment 4 demonstrates that causal superseding can occur with violations of non-moral norms. We propose a model of the superseding effect based on the idea of counterfactual sufficiency.

People sometimes explain behavior by appealing to an essentialist concept of the self, often referred to as the true self. Existing studies suggest that people tend to believe that the true self is morally virtuous; that is deep inside, every person is motivated to behave in morally good ways. Is this belief particular to individuals with optimistic beliefs or people from Western cultures, or does it reflect a widely held cognitive bias in how people understand the self? To address this question, we tested the good true self theory against two potential boundary conditions that are known to elicit different beliefs about the self as a whole. Study 1 tested whether individual differences in misanthropy—the tendency to view humans negatively—predict beliefs about the good true self in an American sample. The results indicate a consistent belief in a good true self, even among individuals who have an explicitly pessimistic view of others. Study 2 compared true self-attributions across cultural groups, by comparing samples from an independent country and a diverse set of interdependent countries. Results indicated that the direction and magnitude of the effect are comparable across all groups we tested. The belief in a good true self appears robust across groups varying in cultural orientation or misanthropy, suggesting a consistent psychological tendency to view the true self as morally good.

We present experimental evidence that people's modes of social interaction influence their construal of truth. Participants who engaged in cooperative interactions were less inclined to agree that there was an objective truth about that topic than were those who engaged in a competitive interaction. Follow-up experiments ruled out alternative explanations and indicated that the changes in objectivity are explained by argumentative mindsets: When people are in cooperative arguments, they see the truth as more subjective. These findings can help inform research on moral objectivism and, more broadly, on the distinctive cognitive consequences of different types of social interaction.

People’s beliefs about normality play an important role in many aspects of cognition and life (e.g., causal cognition, linguistic semantics, cooperative behavior). But how do people determine what sorts of things are normal in the first place? Past research has studied both people’s representations of statistical norms (e.g., the average) and their representations of prescriptive norms (e.g., the ideal). Four studies suggest that people’s notion of normality incorporates both of these types of norms. In particular, people’s representations of what is normal were found to be influenced both by what they believed to be descriptively average and by what they believed to be prescriptively ideal. This is shown across three domains: people’s use of the word ‘‘normal” (Study 1), their use of gradable adjectives (Study 2), and their judgments of concept prototypicality (Study 3). A final study investigated the learning of normality for a novel category, showing that people actively combine statistical and prescriptive information they have learned into an undifferentiated notion of what is normal (Study 4). Taken together, these findings may help to explain how moral norms impact the acquisition of normality and, conversely, how normality impacts the acquisition of moral norms.

Generic statements express generalizations about categories. Current theories suggest that people should be especially inclined to accept generics that involve threatening information. However, previous tests of this claim have focused on generics about non-human categories, which raises the question of whether this effect applies as readily to human categories. In Experiment 1, adults were more likely to accept generics involving a threatening property for artifacts, but this negativity bias did not also apply to human categories. Experiment 2 examined an alternative hypothesis for this result, and Experiments 3 and 4 served as conceptual replications of the first experiment. Experiment 5 found that even preschoolers apply generics differently for humans and artifacts. Finally, Experiment 6 showed that these effects reflect differences between human and non-human categories more generally, as adults showed a negativity bias for categories of non-human animals, but not for categories of humans. These findings suggest the presence of important, early-emerging domain differences in people's judgments about generics.

Over the past several decades, psychological essentialism has been an important topic of study, incorporating research from multiple areas of psychology, philosophy and linguistics. At its most basic level, essentialism is the tendency to represent certain concepts in terms of a deeper, unobservable property that is responsible for category membership. Originally, this concept was used to understand people’s reasoning about natural kind concepts, such as TIGER and WATER, but more recently, researchers have identified the emergence of essentialist-like intuitions in a number of other contexts, including people’s representation of concepts like SCIENTIST or CHRISTIAN. This paper develops an account that aims to capture how essentialism may operate across these varied cases. In short, we argue that while there is diversity in the forms essentialism can take, these varied cases reflect the same underlying cognitive structure.

It has been hypothesized that actors tend to attribute behavior to the situation whereas observers tend to attribute behavior to the person (Jones & Nisbett 1972). The authors argue that this simple hypothesis fails to capture the complexity of actual actor-observer differences in people’s behavioral explanations. A new framework is proposed in which reason explanations are distinguished from explanations that cite causes, especially stable traits. With this framework in place, it becomes possible to show that there are a number of distinct actorobserver asymmetries in explanation, each stemming from a distinct psychological process by which explanations are generated.

Four studies explored people's judgments about whether particular types of behavior are compatible with determinism. Participants read a passage describing a deterministic universe, in which everything that happens is fully caused by whatever happened before it. They then assessed the degree to which different behaviors were possible in such a universe. Other participants evaluated the extent to which each of these behaviors had various features. We assessed the extent to which these features predicted judgments about whether the behaviors were possible in a deterministic universe. Experiments 1 and 2 found that people's judgments about whether a behavior was compatible with determinism were not predicted by their judgments about whether that behavior relies on physical processes in the brain and body, is uniquely human, is unpredictable, or involves reasoning. Experiment 3, however, found that a distinction between what we call “active” and “passive” behaviors can explain people's judgments. Experiment 4 extended these findings, showing that we can measure this distinction in several ways and that it is robustly predicted by two different cues. Taken together, these results suggest that people carve up mentally guided behavior into two distinct types—understanding one type to be compatible with determinism, but another type to be fundamentally incompatible with determinism.

Five experiments provide evidence for a class of ‘dual character concepts.’ Dual character concepts characterize their members in terms of both (a) a set of concrete features and (b) the abstract values that these features serve to realize. As such, these concepts provide two bases for evaluating category members and two different criteria for category membership. Experiment 1 provides support for the notion that dual character concepts have two bases for evaluation. Experiments 2-4 explore the claim that dual character concepts have two different criteria for category membership. The results show that when an object possesses the appropriate concrete features, but does not fulfill the appropriate abstract value, it is judged to be a category member in one sense but not in another. Finally, Experiment 5 uses the theory developed here to construct artificial dual character concepts and examines whether participants react to these artificial concepts in the same way as naturally occurring dual character concepts. The present studies serve to define the nature of dual character concepts and distinguish them from other types of concepts (e.g., natural kind concepts), which share some, but not all of the properties of dual character concepts. More broadly, these phenomena suggest a normative dimension in everyday conceptual representation.

It is often implied, and sometimes explicitly asserted, that folk psychology is best understood as a kind of predictive device. The key contention of this widely held view is that people apply folk-psychological concepts because the application of these concepts enables them to predict future behavior. If we know what an agent believes, desires, intends, etc., we can make a pretty good guess about what he or she will do next. It seems to me that this picture is not quite right. In a series of recent papers, my colleagues and I have presented data that suggests that moral considerations actually play an important role in folk psychology (Knobe 2003a; 2003b; 2004; Knobe & Burra forthcoming; Knobe & Mendlow forthcoming). These findings do not sit well with the view according to which folk psychology is best understood as a predictive device. It appears that folk psychology might be better understood as a kind of multi-purpose tool. It is used not only in making predictive judgments but also in making moral judgments, and both of these uses appear to have shaped the fundamental competencies that underlie it. One of the most important forms of evidence in this debate comes from studies of the distinction people draw between intentional and unintentional behavior. These studies indicate that people’s intuitions as to whether or not a behavior was performed intentionally can be influenced by their beliefs about the moral status of the behavior..

Two studies demonstrate that a dispositional proneness to disgust (“disgust sensitivity”) is associated with intuitive disapproval of gay people. Study 1 was based on previous research showing that people are more likely to describe a behavior as intentional when they see it as morally wrong (see Knobe, 2006, for a review). As predicted, the more disgust sensitive participants were, the more likely they were to describe an agent whose behavior had the side effect of causing gay men to kiss in public as having intentionally encouraged gay men to kiss publicly— even though most participants did not explicitly think it wrong to encourage gay men to kiss in public. No such effect occurred when subjects were asked about heterosexual kissing. Study 2 used the Implicit Association Test (IAT; Nosek, Banaji, & Greenwald, 2006) as a dependent measure. The more disgust sensitive participants were, the more they showed..

It has sometimes been suggested that people represent the structure of action in terms of an action tree. A question now arises about the relationship between this action tree representation and people’s moral judgments. A natural hypothesis would be that people first construct a representation of the action tree and then go on to use this representation in making moral judgments. The present paper argues for a more complex view. Specifically, the paper reports a series of experimental studies that appear to show that people’s moral judgments can actually impact their representations of the action tree itself