The conjunction fallacy occurs when people judge a conjunction A&B as more likely than a constituent A, contrary to the rules of probability theory. We describe a model where this fallacy arises purely as a consequence of noise and random error in the probability estimation process. We describe an experiment testing this proposal by assessing the relationship between fallacy rates and the avera...

AN IMPORTANT SOURCE of current misunderstanding and controversy about diet-disease relationships is the inappropriate extrapolation of evidence from group data to the individual and vice versa. In this editorial piece the difference is illustrated between correlations of risk factors and disease found in individuals and those found between populations. An attempt is made to clarify the causal i...

Recent papers have demonstrated that the way people acquire information about a decision problem, by experience or by abstract description, can affect their behavior. We examined the role of experience over time in the emergence of the Gambler’s Fallacy in binary prediction tasks. Theories of the Gambler’s Fallacy and models of binary prediction suggest that recency bias, elicited by experience...

In this paper, an analysis is given of the straw man fallacy as a misrepresentation of someone's commitments in order to refute that person's argument. With this analysis a distinction can be made between straw man and other closely related fallacies such as ad hominem, secundum quid and ad verecundiam. When alleged cases of the straw man fallacy are evaluated, the speaker's commitment should b...

Attributing higher “probability” to a sentence of form p-and-q compared to p is a reasoning fallacy only if (a) the word “probability” carries its modern, technical meaning, and (b) the sentence p is interpreted as a conjunct of the conjunction p-and-q. Legitimate doubts arise about both conditions in classic demonstrations of the conjunction fallacy. We use betting paradigms to reduce these so...

The authors identify and offer an analysis of a new form of the Straw Man fallacy, and then explore the implications of the prevalence of this fallacy for contemporary political discourse.

Information generally comes from less than fully reliable sources. Rationality, it seems, requires that one take source reliability into account when reasoning on the basis of such information. Recently, Bovens and Hartmann (2003) proposed an account of the conjunction fallacy based on this idea. They show that, when statements in conjunction fallacy scenarios are perceived as coming from such ...