Joshua Knobe

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.

Existing research suggests that people's judgments of actual causation can be influenced by the degree to which they regard certain events as normal. We develop an explanation for this phenomenon that draws on standard tools from the literature on graphical causal models and, in particular, on the idea of probabilistic sampling. Using these tools, we propose a new measure of actual causal strength. This measure accurately captures three effects of normality on causal judgment that have been observed in existing studies. More importantly, the measure predicts a new effect ("abnormal deflation"). Two studies show that people's judgments do, in fact, show this new effect. Taken together, the patterns of people's causal judgments thereby provide support for the proposed explanation.

Experimental studies suggest that people’s ordinary causal judgments are affected not only by statistical considerations but also by moral considerations. One way to explain these results would be to construct a model according to which people are trying to make a purely statistical judgment but moral considerations somehow distort their intuitions. The present paper offers an alternative perspective. Specifically, the author proposes a model according to which the very same underlying mechanism accounts for the influence of both statistical and moral considerations. On this model, it appears that ordinary causal judgments are quite different from the sorts of judgments one might find in the systematic sciences.Keywords: Causation; Causal cognition; Experimental philosophy; Cognitive science.

It is widely believed that the primary function of folk psychology lies in the prediction, explanation and control of behavior. A question arises, however, as to whether folk psychology has also been shaped in fundamental ways by the various other roles it plays in people’s lives. Here I approach that question by considering one particular aspect of folk psychology – the distinction between intentional and unintentional behaviors. The aim is to determine whether this distinction is best understood as a tool used in prediction, explanation and control or whether it has been shaped in fundamental ways by some other aspect of its use.

According to models of objectification, viewing someone as a body induces de-mentalization, stripping away their psychological traits. Here evidence is presented for an alternative account, where a body focus does not diminish the attribution of all mental capacities but, instead, leads perceivers to infer a different kind of mind. Drawing on the distinction in mind perception between agency and experience, it is found that focusing on someone's body reduces perceptions of agency but increases perceptions of experience. These effects were found when comparing targets represented by both revealing versus nonrevealing pictures or by simply directing attention toward physical characteristics. The effect of a body focus on mind perception also influenced moral intuitions, with those represented as a body seen to be less morally responsible but more sensitive to harm. These effects suggest that a body focus does not cause objectification per se but, instead, leads to a redistribution of perceived mind.

The philosophical study of mind in the twentieth century was dominated by a research program that used a priori methods to address foundational questions. Since that time, however, the philosophical study of mind has undergone a dramatic shift. To provide a more accurate picture of contemporary philosophical work, I compared a sample of highly cited philosophy papers from the past five years with a sample of highly cited philosophy papers from the twentieth century. In the twentieth century sample, the majority of papers used purely a priori methods, while only a minority cited results from empirical studies. In the sample from the past five years, the methodology is radically different. The majority of papers cite results from empirical studies, a sizable proportion report original experimental results, and only a small minority are purely a priori. Overall, the results of the review suggest that the philosophical study of mind has become considerably more integrated into the broader interdisciplinary field of cognitive science.

The concept of innateness appears in systematic research within cognitive science, but it also appears in less systematic modes of thought that long predate the scientific study of the mind. The present studies therefore explore the relationship between the properly scientific uses of this concept and its role in ordinary folk understanding. Studies 1-4 examined the judgments of people with no specific training in cognitive science. Results showed (a) that judgments about whether a trait was innate were not affected by whether or not the trait was learned, but (b) such judgments were impacted by moral considerations. Study 5 looked at the judgments of both non-scientists and scientists, in conditions that encouraged either thinking about individual cases or thinking about certain general principles. In the case-based condition, both non-scientists and scientists showed an impact of moral considerations but little impact of learning. In the principled condition, both non-scientists and scientists showed an impact of learning but little impact of moral considerations. These results suggest that both non-scientists and scientists are drawn to a conception of innateness that differs from the one at work in contemporary scientific research but that they are also both capable of 'filtering out' their initial intuitions and using a more scientific approach.

When people are trying to determine whether an entity is capable of having certain kinds of mental states, they can proceed either by thinking about the entity from a *functional* standpoint or by thinking about the entity from a *physical* standpoint. We conducted a series of studies to determine how each of these standpoints impact people’s mental state ascriptions. The results point to a striking asymmetry. It appears that ascriptions of states involving phenomenal consciousness are sensitive to physical factors in a way that ascriptions of other states are not

Kauppinen argues that experimental philosophy cannot help us to address questions about the semantics of our concepts and that it therefore has little to contribute to the discipline of philosophy. This argument raises fascinating questions in the philosophy of language, but it is simply a red herring in the present context. Most researchers in experimental philosophy were not trying to resolve semantic questions in the first place. Their aim was rather to address a more traditional sort of question, the sort of question that was regarded as absolutely central in the period before the rise of analytic philosophy.

Consider the following explanation: (1) George took his umbrella because it was just about to rain. This is an explanation of a quite distinctive sort. It is profoundly different from the sort of explanation we might use to explain, say, the movements of a bouncing ball or the gradual rise of the tide on a beach. Unlike these other types of explanations, it explains an agent’s behavior by describing the agent’s own _reasons_ for performing that behavior. Explanations that work in this way have a number of distinctive and important properties, and we will refer to them here as _reason explanations_. Looking at the use of reason explanations with a philosophical eye, one is apt to experience a certain puzzlement. One wants to know precisely what makes a given reason explanation true or false. So, for example, the explanation given above seems to be saying that George’s reason for taking his umbrella was that it was just about to rain. But what exactly makes it the case that this is George’s reason? Does he have to actually be.

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..