Simple Heuristics That Make Us Smart invites readers to embark on a new journey into a land of rationality that differs from the familiar territory of cognitive science and economics. Traditional views of rationality tend to see decision makers as possessing superhuman powers of reason, limitless knowledge, and all of eternity in which to ponder choices. To understand decisions in the real world, we need a different, more psychologically plausible notion of rationality, and this book provides it. It is about (...) fast and frugal heuristics--simple rules for making decisions when time is pressing and deep thought an unaffordable luxury. These heuristics can enable both living organisms and artificial systems to make smart choices, classifications, and predictions by employing bounded rationality. But when and how can such fast and frugal heuristics work? Can judgments based simply on one good reason be as accurate as those based on many reasons? Could less knowledge even lead to systematically better predictions than more knowledge? Simple Heuristics explores these questions, developing computational models of heuristics and testing them through experiments and analyses. It shows how fast and frugal heuristics can produce adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high school drop out rates, and playing the stock market. As an interdisciplinary work that is both useful and engaging, this book will appeal to a wide audience. It is ideal for researchers in cognitive psychology, evolutionary psychology, and cognitive science, as well as in economics and artificial intelligence. It will also inspire anyone interested in simply making good decisions. (shrink)

We must restrict to mere probability not only statements of comparatively great uncertainty, like predictions about the weather, where we would cautiously ...

Mainstream epistemology is a highly theoretical and abstract enterprise. Traditional epistemologists rarely present their deliberations as critical to the practical problems of life, unless one supposes—as Hume, for example, did not—that skeptical worries should trouble us in our everyday affairs. But some issues in epistemology are both theoretically interesting and practically quite pressing. That holds of the problem to be discussed here: how laypersons should evaluate the testimony of experts and decide which of two or more rival experts is most (...) credible. It is of practical importance because in a complex, highly specialized world people are constantly confronted with situations in which, as comparative novices, they must turn to putative experts for intellectual guidance or assistance. It is of theoretical interest because the appropriate epistemic considerations are far from transparent; and it is not clear how far the problems lead to insurmountable skeptical quandaries. This paper does not argue for flat-out skepticism in this domain; nor, on the other hand, does it purport to resolve all pressures in the direction of skepticism. It is an exploratory paper, which tries to identify problems and examine some possible solutions, not to establish those solutions definitively. (shrink)

The standard philosophical project of analysing the concept of knowledge has radical defects in its arbitrary restriction of the subject matter, and its risky theoretical presuppositions. Edward Craig suggests a more illuminating approach, akin to the `state of nature' method found in political theory, which builds up the concept from a hypothesis about the social function of knowledge and the needs it fulfils. Light is thrown on much that philosophers have written about knowledge, about its analysis and the obstacles to (...) its analysis, and on the debate over scepticism. It becomes apparent why many languages not only have such constructions as `knows whether' and `knows that', but also have equivalents of `knows how to' and `know' followed by a direct object. Thus the inquiry is both broadened in scope and made theoretically less fragile. (shrink)

Contrary to formal theories of induction, I argue that there are no universal inductive inference schemas. The inductive inferences of science are grounded in matters of fact that hold only in particular domains, so that all inductive inference is local. Some are so localized as to defy familiar characterization. Since inductive inference schemas are underwritten by facts, we can assess and control the inductive risk taken in an induction by investigating the warrant for its underwriting facts. In learning more facts, (...) we extend our inductive reach by supplying more localized inductive inference schemes. Since a material theory no longer separates the factual and schematic parts of an induction, it proves not to be vulnerable to Hume's problem of the justification of induction. (shrink)

This paper focuses on the question of how to resolve disagreement and uses the Lehrer-Wagner model as a formal tool for investigating consensual decision-making. The main result consists in a general definition of when agents treat each other as epistemic peers (Kelly 2005; Elga 2007), and a theorem vindicating the “equal weight view” to resolve disagreement among epistemic peers. We apply our findings to an analysis of the impact of social network structures on group deliberation processes, and we demonstrate their (...) stability with the help of numerical simulations. (shrink)

Testimony is indispensable in the sciences. To deny the propriety of relying on it engenders an untenable scepticism. But this leaves open the issue of what exactly confers a scientist’s epistemic right to rely upon the word of her colleagues. Some authors have suggested a recipient of testimony enjoys an epistemic entitlement to trust the word of another as such, not requiring evidence of her trustworthiness, so long as there is not evidence of her untrustworthiness. I argue that, whether or (...) not such an on-no-evidence entitlement to believe what one is told exists, it shrinks to irrelevance in the explanation of the basis on which scientists take each other’s word in the scientific community. This is so, since a normally knowledgeable adult hearer is typically awash with relevant evidence, direct and circumstantial, for and against, concerning a teller’s trustworthiness, and this swamps any alleged entitlement to believe in the absence of such evidence. There need not be personal knowledge of the teller, since social role and topic provide evidence regarding trustworthiness. I also discuss the individuation of ‘testimony’ as an epistemic kind. I suggest that we should not attempt to define a category with sharp boundaries, but instead characterise a paradigm case—one person telling another something in face-to-face personal communication—and then notice other cases which both resemble and diverge from this in epistemically relevant features—lectures, media broadcasts, personal letters, personal diaries, etc.Author Keywords: Testimony; Justification; Knowledge; Individualism; Communication. (shrink)

This article suggests a ‘best alternative' justification of induction (in the sense of Reichenbach) which is based on meta-induction . The meta-inductivist applies the principle of induction to all competing prediction methods which are accessible to her. It is demonstrated, and illustrated by computer simulations, that there exist meta-inductivistic prediction strategies whose success is approximately optimal among all accessible prediction methods in arbitrary possible worlds, and which dominate the success of every noninductive prediction strategy. The proposed justification of meta-induction is (...) mathematically analytical. It implies, however, an a posteriori justification of object-induction based on the experiences in our world. *Received November 2005; revised March 2008. †To contact the author, please write to: Department of Philosophy, University of Duesseldorf, Universitaetsstrasse 1, Geb. 23.21, Duesseldorf, Germany D-40225; e-mail: [email protected]. (shrink)

In the 2005 Kitzmiller v Dover Area School Board case, a federal district court ruled that Intelligent Design creationism was not science, but a disguised religious view and that teaching it in public schools is unconstitutional. But creationists contend that it is illegitimate to distinguish science and religion, citing philosophers Quinn and especially Laudan, who had criticized a similar ruling in the 1981 McLean v. Arkansas creation-science case on the grounds that no necessary and sufficient demarcation criterion was possible and (...) that demarcation was a dead pseudo-problem. This article discusses problems with those conclusions and their application to the quite different reasoning between these two cases. Laudan focused too narrowly on the problem of demarcation as Popper defined it. Distinguishing science from religion was and remains an important conceptual issue with significant practical import, and philosophers who say there is no difference have lost touch with reality in a profound and perverse way. The Kitzmiller case did not rely on a strict demarcation criterion, but appealed only to a “ballpark” demarcation that identifies methodological naturalism as a “ground rule” of science. MN is shown to be a distinguishing feature of science both in explicit statements from scientific organizations and in actual practice. There is good reason to think that MN is shared as a tacit assumption among philosophers who emphasize other demarcation criteria and even by Laudan himself. (shrink)

It is widely believed that bringing parties with differing opinions together to discuss their differences will help both in securing consensus and also in ensuring that this consensus closely approximates the truth. This paper investigates this presumption using two mathematical and computer simulation models. Ultimately, these models show that increased contact can be useful in securing both consensus and truth, but it is not always beneficial in this way. This suggests one should not, without qualification, support policies which increase interpersonal (...) contact if one seeks to improve the epistemic performance of groups. (shrink)

The justification of induction is of central significance for cross-cultural social epistemology. Different ‘epistemological cultures’ do not only differ in their beliefs, but also in their belief-forming methods and evaluation standards. For an objective comparison of different methods and standards, one needs (meta-)induction over past successes. A notorious obstacle to the problem of justifying induction lies in the fact that the success of object-inductive prediction methods (i.e., methods applied at the level of events) can neither be shown to be universally (...) reliable (Hume's insight) nor to be universally optimal. My proposal towards a solution of the problem of induction is meta-induction. The meta-inductivist applies the principle of induction to all competing prediction methods that are accessible to her. By means of mathematical analysis and computer simulations of prediction games I show that there exist meta-inductive prediction strategies whose success is universally optimal among all accessible prediction strategies, modulo a small short-run loss. The proposed justification of meta-induction is mathematically analytical. It implies, however, an a posteriori justification of object-induction based on the experiences in our world. In the final section I draw conclusions about the significance of meta-induction for the social spread of knowledge and the cultural evolution of cognition, and I relate my results to other simulation results which utilize meta-inductive learning mechanisms. (shrink)

Hegselmann and Krause have developed a simple yet powerful computational model for studying the opinion dynamics in societies of epistemically interacting truth-seeking agents. We present various extensions of this model and show their relevance to the investigation of socio-epistemic questions, with an emphasis on normative questions.

This paper develops a formal framework to model a process in which the formation of individual opinions is embedded in a deliberative exchange with others. The paper opts for a low-resolution modeling approach and abstracts away from most of the details of the social-epistemic process. Taking a bird's eye view allows us to analyze the chances for the truth to be found and broadly accepted under conditions of cognitive division of labour combined with a social exchange process. Cognitive division of (...) labour means that only some individuals are active truth seekers, possibly with different capacities. Both mathematical tools and computer simulations are used to investigate the model. As an analytical result, the Funnel Theorem states that under rather weak conditions on the social process, a consensus on the truth will be reached if all individuals possess an arbitrarily small capacity to go for the truth. The Leading the pack Theorem states that under certain conditions even a single truth seeker may lead all individuals to the truth. Systematic simulations analyze how close agents can get to the truth depending upon the frequency of truth seekers, their capacities as truth seekers, the position of the truth (more to the extreme or more in the centre of an opinion space), and the willingness to take into account the opinions of others when exchanging and updating opinions. (shrink)

Social epistemology is the normative theory of socioepistemic practices. Teaching is a socioepistemic practice, so educational practices belong on the agenda of social epistemology. A current question is whether intelligent design should be taught in biology classes. This paper focuses on the argument from “fairness” or “equal time.” The principal aim of education is knowledge transmission, but evidence renders it doubtful that giving intelligent design equal time would promote knowledge transmission. In making curricular decisions, boards of education should consult the (...) experts. Are novices capable of identifying genuine experts? This social epistemological question is answered affirmatively. (shrink)

Although I agree with Elqayam & Evans' (E&E's) criticisms of is-ought and ought-is fallacies, I criticize their rejection of normativism on two grounds: (1) Contrary to E&E's assumption, not every normative system of reasoning consists of formal rules. (2) E&E assume that norms of reasoning are grounded on intuition or authority, whereas in contemporary epistemology they have to be justified, primarily by their truth-conduciveness.

In sec. 1.1 I emphasize the meliorative purpose of epistemology, and I characterize Goldman's epistemology as reliabilistic, cognitive, social, and meliorative. In sec. 1.2 I point out that Goldman's weak notion of knowledge is in conflict with our ordinary usage of 'knowledge'. In sec. 2 I argue for an externalist-internalist hybrid conception of justification which adds reliability-indicators to externalist knowledge. Reliability-indicators produce a veritistic surplus value for the social spread of knowledge. In sec. 3 I analyze some particular meliorative rules (...) which have been proposed by Goldman. I prove that obedience to the rule of maximally specific evidence increases expected veritistic value (sec. 3.1), and I argue that rule-circular arguments are epistemically worthless (sec. 3.2). In the final sec. 3.3 I report a non-circular justification of meta-induction which has been developed elsewhere. (shrink)