Assertion is fundamental to our lives as social and cognitive beings. Philosophers have recently built an impressive case that the norm of assertion is factive. That is, you should make an assertion only if it is true. Thus far the case for a factive norm of assertion been based on observational data. This paper adds experimental evidence in favor of a factive norm from six studies. In these studies, an assertion’s truth value dramatically affects whether people think it should be (...) made. Whereas nearly everyone agreed that a true assertion supported by good evidence should be made, most people judged that a false assertion supported by good evidence should not be made. The studies also suggest that people are consciously aware of criteria that guide their evaluation of assertions. Evidence is also presented that some intuitive support for a non-factive norm of assertion comes from a surprising tendency people have to misdescribe cases of blameless rule-breaking as cases where no rule is broken. (shrink)

Recent work has assumed that the normativity associated with assertion differs from the normativity of morality, practical rationality, etiquette, and legality. That is, whether an assertion “should” be made is not merely a function of these other familiar sorts of normativity and is especially connected to truth. Some researchers have challenged this assumption of distinctive normativity. In this paper I report two experiments that test the assumption. Participants read a brief story, judged whether an assertion should be made, and rated (...) several other qualities of the assertion, including its truth value, morality, rationality, etiquette, legality, and folly. Of these qualities, truth value most strongly predicted assertability. The findings support the assumption of distinctive normativity and provide further evidence that the norm of our social practice of assertion is factive. (shrink)

Researchers have debated whether knowledge or certainty is a better candidate for the norm of assertion. Should you make an assertion only if you know it's true? Or should you make an assertion only if you're certain it's true? If either knowledge or certainty is a better candidate, then this will likely have detectable behavioral consequences. I report an experiment that tests for relevant behavioral consequences. The results support the view that assertability is more closely linked to knowledge than to (...) certainty. In multiple scenarios, people were much more willing to allow assertability and certainty to come apart than to allow assertability and knowledge to come apart. (shrink)

Five experiments demonstrate the central role of knowledge attributions in social evaluations. In Experiments 1–3, we manipulated whether an agent believes, is certain of, or knows a true proposition and asked people to rate whether the agent should perform a variety of actions. We found that knowledge, more so than belief or certainty, leads people to judge that the agent should act. In Experiments 4–5, we investigated whether attributions of knowledge or certainty can explain an important finding on how people (...) act based on statistical evidence, known as “the Wells effect”. We found that knowledge attributions, but not certainty attributions, mediate this effect on decision making. 2018 APA, all rights reserved). (shrink)

Communication is essential to human society, and assertion is central to communication. This article reviews evidence from life science, cognitive science, and philosophy relevant to understanding how our social practice of assertion is structured and sustained. The principal conclusion supported by this body of evidence is that knowledge is a central norm of assertion—that is, according to the rules of the practice, assertions should express knowledge.

According to factive accounts of the norm of belief and decision-making, you should not believe or base decisions on a falsehood. Even when the evidence misleadingly suggests that a false proposition is true, you should not believe it or base decisions on it. Critics claim that factive accounts are counterintuitive and badly mischaracterize our ordinary practice of evaluating beliefs and decisions. This paper reports four experiments that rigorously test the critic’s accusations and the viability of factive accounts. The results undermine (...) the accusations and provide the best evidence yet of factive norms of belief and decision-making. The results also help discriminate between two leading candidates for a factive norm: truth and knowledge. Knowledge is the superior candidate. (shrink)

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. (shrink)

In the remainder of this article, we will disarm an important motivation for epistemic contextualism and interest-relative invariantism. We will accomplish this by presenting a stringent test of whether there is a stakes effect on ordinary knowledge ascription. Having shown that, even on a stringent way of testing, stakes fail to impact ordinary knowledge ascription, we will conclude that we should take another look at classical invariantism. Here is how we will proceed. Section 1 lays out some limitations of previous (...) research on stakes. Section 2 presents our study and concludes that there is little evidence for a substantial stakes effect. Section 3 responds to objections. The conclusion clears the way for classical invariantism. (shrink)

This article examines whether people share the Gettier intuition (viz. that someone who has a true justified belief that p may nonetheless fail to know that p) in 24 sites, located in 23 countries (counting Hong Kong as a distinct country) and across 17 languages. We also consider the possible influence of gender and personality on this intuition with a very large sample size. Finally, we examine whether the Gettier intuition varies across people as a function of their disposition to (...) engage in “reflective” thinking. (shrink)

In this article, we present evidence that in four different cultural groups that speak quite different languages there are cases of justified true beliefs that are not judged to be cases of knowledge. We hypothesize that this intuitive judgment, which we call “the Gettier intuition,” may be a reflection of an underlying innate and universal core folk epistemology, and we highlight the philosophical significance of its universality.

We report a series of experiments examining whether people ascribe knowledge for true beliefs based on probabilistic evidence. Participants were less likely to ascribe knowledge for beliefs based on probabilistic evidence than for beliefs based on perceptual evidence or testimony providing causal information. Denial of knowledge for beliefs based on probabilistic evidence did not arise because participants viewed such beliefs as unjustified, nor because such beliefs leave open the possibility of error. These findings rule out traditional philosophical accounts for why (...) probabilistic evidence does not produce knowledge. The experiments instead suggest that people deny knowledge because they distrust drawing conclusions about an individual based on reasoning about the population to which it belongs, a tendency previously identified by “judgment and decision making” researchers. Consistent with this, participants were more willing to ascribe knowledge for beliefs based on probabilistic evidence that is specific to a particular case. 2016 APA, all rights reserved). (shrink)

Nearly all philosophers agree that only true things can be known. But does this principle reflect actual patterns of ordinary usage? Several examples in ordinary language seem to show that ‘know’ is literally used non-factively. By contrast, this paper reports five experiments utilizing explicit paraphrasing tasks, which suggest that non-factive uses are actually not literal. Instead, they are better explained by a phenomenon known as protagonist projection. It is argued that armchair philosophical orthodoxy regarding the truth requirement for knowledge withstands (...) current empirical scrutiny. (shrink)

Knobe (2003a, 2003b, 2004b) and others have demonstrated the surprising fact that the valence of a side-effect action can affect intuitions about whether that action was performed intentionally. Here we report the results of an experiment that extends these findings by testing for an analogous effect regarding knowledge attributions. Our results suggest that subjects are less likely to find that an agent knows an action will bring about a side-effect when the effect is good than when it is bad. It (...) is further argued that these findings, while preliminary, have important implications for recent debates within epistemology about the relationship between knowledge and action. (shrink)

I review recent work from armchair and cross-cultural epistemology on whether humans possess a knowledge concept as part of a universal “folk epistemology.” The work from armchair epistemology fails because it mischaracterizes ordinary knowledge judgments. The work from cross-cultural epistemology provides some defeasible evidence for a universal folk epistemology. I argue that recent findings from comparative psychology establish that humans possess a species-typical knowledge concept. More specifically, recent work shows that knowledge attributions are a central part of primate social cognition, (...) used to predict others’ behavior and guide decision-making. The core primate knowledge concept is that of truth detection (across different sensory modalities) and retention (through memory) and may also include rudimentary forms of indirect truth discovery through inference. In virtue of their evolutionary heritage, humans inherited the primate social-cognitive system and thus share this core knowledge concept. (shrink)

One of science's greatest intellects examines how people and animals display fear, anger, and pleasure. Darwin based this 1872 study on his personal observations, which anticipated later findings in neuroscience. Abounding in anecdotes and literary quotations, the book is illustrated with 21 figures and seven photographic plates. Its direct approach, accessible to professionals and amateurs alike, continues to inspire and inform modern research in psychology.

Language is a human universal reflecting our deeply social nature. Among its essential functions, language enables us to quickly and efficiently share information. We tell each other that many things are true—that is, we routinely make assertions. Information shared this way plays a critical role in the decisions and plans we make. In Knowledge and the Norm of Assertion, a distinguished philosopher and cognitive scientist investigates the rules or norms that structure our social practice of assertion. Combining evidence from philosophy, (...) psychology, and biology, John Turri shows that knowledge is the central norm of assertion and explains why knowledge plays this role. -/- Concise, comprehensive, non-technical, and thoroughly accessible, this volume quickly brings readers to the cutting edge of a major research program at the intersection of philosophy and science. It presupposes no philosophical or scientific training. It will be of interest to philosophers and scientists, is suitable for use in graduate and undergraduate courses, and will appeal to general readers interested in human nature, social cognition, and communication. (shrink)

Encyclopedia entry covering the growing literature on the Knowledge Norm of Assertion (and its rivals), the Knowledge Norm of Action (and pragmatic encroachment), the Knowledge Norm of Belief, and the Knowledge Norm of Disagreement.

This article examines whether people share the Gettier intuition (viz. that someone who has a true justified belief that p may nonetheless fail to know that p) in 24 sites, located in 23 countries (counting Hong-Kong as a distinct country) and across 17 languages. We also consider the possible influence of gender and personality on this intuition with a very large sample size. Finally, we examine whether the Gettier intuition varies across people as a function of their disposition to engage (...) in “reflective” thinking. (shrink)