Ori Friedman

How do people decide which claims should be considered mere beliefs and which count as knowledge? Although little is known about how people attribute knowledge to others, philosophical debate about the nature of knowledge may provide a starting point. Traditionally, a belief that is both true and justified was thought to constitute knowledge. However, philosophers now agree that this account is inadequate, due largely to a class of counterexamples (termed ‘‘Gettier cases’’) in which a person’s justified belief is true, but only due to luck. We report four experiments examining the effect of truth, justification, and ‘‘Gettiering’’ on people’s knowledge attributions. These experiments show that: (1) people attribute knowledge to others only when their beliefs are both true and justified; (2) in contrast to contemporary philosophers, people also attribute knowledge to others in Gettier situations; and (3) knowledge is not attributed in one class of Gettier cases, but only because the agent’s belief is based on ‘‘apparent’’ evidence. These findings suggest that the lay concept of knowledge is roughly consistent with the traditional account of knowledge as justified true belief, and also point to a major difference between the epistemic intuitions of laypeople and those of philosophers.

Young children’s failures in reasoning about beliefs and desires, and especially about false beliefs, have been much studied. However, there are few accounts of successful belief-desire reasoning in older children or adults. An exception to this is a model in which belief attribution is treated as a process wherein an inhibitory system selects the most likely content for the belief to be attributed from amongst several competing contents [Leslie, A. M., & Polizzi, P. (1998). Developmental Science, 1, 247–254]. We tested this model with an ‘avoidance false belief task’ in which subjects predict the behavior of a character, who wants to avoid an object but who is mistaken about which of three locations it is in. The task has two equally correct answers—in seeking to avoid the location where she mistakenly believes the object to be, the character might equally go to the location where the object actually is, or to the remaining empty location. However, the model predicts that subjects will prefer one of these answers, selecting the object’s actual location over the empty location. This bias was confirmed in a series of five experiments with children aged between 4 and 8 years of age. A sixth experiment ruled out two rival explanations for children’s biased responding. Two further experiments found the opposite bias in adults. These findings support one selection model as an account of belief-desire reasoning in children, and suggest that a different model is needed for adults. The process of selecting contents for mental state attributions shows a developmental shift between 8 years of age and adulthood.

Owned objects are typically viewed as non-fungible-they cannot be freely interchanged. We report three experiments (total N=312) demonstrating this intuition in preschool-aged children. In Experiment 1, children considered an agent who takes one of two identical objects and leaves the other for a peer. Children viewed this as acceptable when the agent took his own item, but not when he took his peer's item. In Experiment 2, children considered scenarios where one agent took property from another. Children said the victim could take back her own property from the perpetrator, but that she could not take an identical object belonging to the perpetrator. Finally, in Experiment 3A and 3B, children considered scenarios where a teacher could give a child either of two objects to play with-an object that the child had recently played with, or another object that looked the same. Children were more likely to say that the teacher should give the object recently played with when it belonged to the child, compared with when it belonged to the teacher. These findings are informative about the basis of judgments that property is non-fungible, and about young children's representation of ownership rights. They show that children's representation of ownership rights is not limited to principles protecting owners from being deprived. Our findings instead suggest that ownership rights are viewed as pertaining to individual objects.

People often judge it unacceptable to directly harm a person, even when this is necessary to produce an overall positive outcome, such as saving five other lives. We demonstrate that similar judgments arise when people consider damage to owned objects. In two experiments, participants considered dilemmas where saving five inanimate objects required destroying one. Participants judged this unacceptable when it required violating another’s ownership rights, but not otherwise. They also judged that sacrificing another’s object was less acceptable as a means than as a side-effect; judgments did not depend on whether property damage involved personal force. These findings inform theories of moral decision-making. They show that utilitarian judgment can be decreased without physical harm to persons, and without personal force. The findings also show that the distinction between means and side-effects influences the acceptability of damaging objects, and that ownership impacts utilitarian moral judgment.

Nagel, San Juan, and Mar report an experiment investigating lay attributions of knowledge, belief, and justification. They suggest that, in keeping with the expectations of philosophers, but contra recent empirical findings [Starmans, C. & Friedman, O. (2012). The folk conception of knowledge. Cognition, 124, 272–283], laypeople consistently deny knowledge in Gettier cases, regardless of whether the beliefs are based on ‘apparent’ or ‘authentic’ evidence. In this reply, we point out that Nagel et al. employed a questioning method that biased participants to deny knowledge. Moreover, careful examination of participants’ responses reveals that they attributed knowledge in Gettier cases. We also note that Nagel et al. misconstrue the distinction between ‘apparent’ and ‘authentic’ evidence, and use scenarios that do not feature the structure that characterizes most Gettier cases. We conclude that NS&M’s findings are fully compatible with the claim that laypeople attribute knowledge in Gettier cases in general, but are significantly less likely to attribute knowledge when a belief is generated based on apparent evidence.

A basic problem of daily life is determining who owns what. One way that people may solve this problem is by relying on a ‘first possession’ heuristic, according to which the first person who possesses an object is its owner, even if others subsequently possess the object. We investigated preschoolers’ use of this heuristic in five experiments. In Experiments 1 and 2, 3- and 4-year-olds inferred that an object was owned by the character who possessed it first, even though another character subsequently possessed it. Two-year-olds also showed this bias, but only when the object was placed between the characters when children were asked about ownership. Experiment 3 ruled out the possibility that children’s bias to select the first possessor results from a tendency to select the character first associated with the object. Experiment 4 showed that 3- and 4-year-olds have difficulty disregarding the first possession heuristic, even when provided with evidence that the character who first possessed an object is not its owner. But Experiment 5 found that children can disregard the heuristic in at least some situations. These five experiments suggest that the first possession heuristic guides children’s ownership inferences. The findings provide the first evidence that preschoolers can infer who owns what, when not explicitly told, and when not reasoning about objects with which they are personally acquainted.

How is ownership established over non-owned things? We suggest that people may view ownership as a kind of credit given to agents responsible for making possession of a non-owned object possible. On this view, judgments about the establishment of ownership depend on attributions of responsibility. We report three experiments showing that people’s judgments about the establishment of ownership are influenced by an agent’s intent and control in bringing about an outcome, factors that also affect attributions of responsibility. These findings demonstrate that people do not just consider who was first to possess an object in judging who owns it, and are broadly consistent with the view that ownership is acquired through labor. The findings also suggest that rather than exclusively being the product of social conventions, judgments about the establishment of ownership over non-owned things also depend on the psychological processes underlying the attribution of responsibility.

We investigated whether the personal importance of objects influences utilitarian decision-making in which damaging property is necessary to produce an overall positive outcome. In Experiment 1, participants judged saving five objects by destroying a sixth object to be less acceptable when the action required destroying the sixth object directly (rather than as a side-effect) and the objects were personally important (rather than unimportant). In Experiment 2, we demonstrated that utilitarian judgments were not influenced by the objects’ monetary worth. Together these findings suggest that personal importance underlies people’s sensitivity to damaging property as a means for utilitarian gains.

Understanding ownership rights is necessary for socially appropriate behavior. We provide evidence that preschoolers' and adults' judgments of ownership rights are related to their judgments of bodily rights. Four-year-olds and adults evaluated the acceptability of harmless actions targeting owned property and body parts. At both ages, evaluations did not vary for owned property or body parts. Instead, evaluations were influenced by two other manipulations—whether the target belonged to the agent or another person, and whether that other person approved of the action. Moreover, these manipulations influenced judgments for owned objects and body parts in the same way: When the other person approved of the action, participants' judgments were positive regardless of who the target belonged to. In contrast, when that person disapproved, judgments depended on who the target belonged to. These findings show that young children grasp the importance of approval or consent for ownership rights and bodily rights, and likewise suggest that people's notions of ownership rights are related to their appreciation of bodily rights

How do young children represent pretend play? One possibility is that recognizing and representing pretend play depends on children’s ability to infer the mental states of the person engaged in pretend play (mentalist account). The two dominant alternative possibilities are that children view as a distinctive form of non-representational behavior (behavioral account), and that children represent pretense by temporarily treating objects as though they have fictional or make-believe properties (flagging account). This chapter provides an overview of the debate between these three accounts of pretend play, but then endorses a fourth position according to which children view pretend play as a form of communication, similar in many ways to drawing.

We conducted five experiments that reveal some main contours of the folk epistemology of lotteries. The folk tend to think that you don't know that your lottery ticket lost, based on the long odds ("statistical cases"); by contrast, the folk tend to think that you do know that your lottery ticket lost, based on a news report ("testimonial cases"). We evaluate three previous explanations for why people deny knowledge in statistical cases: the justification account, the chance account, and the statistical account. None of them seems to work. We then propose a new explanation of our own, the formulaic account, according to which some people deny knowledge in statistical cases due to formulaic expression.