Does the formation of delusions involve abnormal reasoning? According to the prominent ‘two-factor’ theory of delusions (e.g. Coltheart, 2007), the answer is yes. The second factor in this theory is supposed to affect a deluded individual's ability to evaluate candidates for belief. However, most published accounts of the two-factor theory have not said much about the nature of this second factor. In an effort to remedy this shortcoming, Coltheart, Menzies and Sutton (2010) recently put forward a Bayesian account of inference (...) in delusions. I outline some criticisms of this important account, and sketch an alternative account of delusional inference that, I argue, avoids these criticisms. Specifically, I argue that the second factor in delusion formation involves a systematic deviation from Bayesian updating, a deviation that may be characterized as a bias towards ‘explanatory adequacy’. I present a numerical model of this idea and show that my alternative account is broadly consistent with prominent prediction error models of delusion formation (e.g. Corlett, Murray et al., 2007). (shrink)

Young and colleagues . Betwixt life and death: case studies of the Cotard delusion. In P. W. Halligan & J. C. Marshall , Method in madness: Case studies in cognitive neuropsychiatry. Mahway, NJ: Lawrence Erlbaum Associates.) have suggested that cases of the Cotard delusion result when a particular perceptual anomaly occurs in the context of an internalising attributional style. This hypothesis has not previously been tested directly. We report here an investigation of attributional style in a 24-year-old woman with Cotard (...) delusion . LU’s attributional style was assessed using the Internal, Personal and Situational Attributions Questionnaire . A new measure of causal locus: the internal, personal and situational attributions questionnaire. Personality and Individual Differences, 20, 261–264.). LU showed a significantly greater proportion of internalising attributions than the control group, both overall and for negative events specifically. The results obtained thus support an association of Cotard delusion with an internalising attributional style, and are therefore consistent with the account of Young and colleagues. The potential brain basis of Cotard delusion is discussed. (shrink)

This paper discusses the ecological case for epistemic innocence: does biased cognition have evolutionary benefits, and if so, does that exculpate human reasoners from irrationality? Proponents of ‘ecological rationality’ have challenged the bleak view of human reasoning emerging from research on biases and fallacies. If we approach the human mind as an adaptive toolbox, tailored to the structure of the environment, many alleged biases and fallacies turn out to be artefacts of narrow norms and artificial set-ups. However, we argue that (...) putative demonstrations of ecological rationality involve subtle locus shifts in attributions of rationality, conflating the adaptive rationale of heuristics with our own epistemic credentials. By contrast, other cases also involve an ecological reframing of human reason, but do not involve such problematic locus shifts. We discuss the difference between these cases, bringing clarity to the rationality debate. (shrink)

The impact of our desires and preferences upon our ordinary, everyday beliefs is well-documented [Gilovich, T. . How we know what isn’t so: The fallibility of human reason in everyday life. New York: The Free Press.]. The influence of such motivational factors on delusions, which are instances of pathological misbelief, has tended however to be neglected by certain prevailing models of delusion formation and maintenance. This paper explores a distinction between two general classes of theoretical explanation for delusions; the motivational (...) and the deficit. Motivational approaches view delusions as extreme instances of self-deception; as defensive attempts to relieve pain and distress. Deficit approaches, in contrast, view delusions as the consequence of defects in the normal functioning of belief mechanisms, underpinned by neuroanatomical or neurophysiological abnormalities. It is argued that although there are good reasons to be sceptical of motivational theories , recent experiments confirm that motives are important causal forces where delusions are concerned. It is therefore concluded that the most comprehensive account of delusions will involve a theoretical unification of both motivational and deficit approaches. (shrink)

Mesoudi et al. overlook an illuminating parallel between cultural and biological evolution, namely, the existence in each realm of a continuum from intelligent, mindful evolution through to oblivious, mindless evolution. In addition, they underplay the independence of cultural fitness from biological fitness. The assumption that successful cultural traits enhance genetic fitness must be sidelined, as must the assumption that such traits will at least be considered worth having. (Published Online November 9 2006).

McKay & Dennett (M&D) suggest that some positive illusions are adaptive. But there is a bidirectional link between memory and positive illusions: Biased autobiographical memories filter incoming information, and self-enhancing information is preferentially attended and used to update memory. Extending M&D's approach, I ask if certain false memories might be adaptive, defending a broad view of the psychosocial functions of remembering.

Humans pay close attention to the reputational consequences of their actions. Recent experiments indicate that even very subtle cues that one is being observed can affect cooperative behaviors. Expressing our opinions about the morality of certain acts is a key means of advertising our cooperative dispositions. Here, we investigated how subtle cues of being watched would affect moral judgments. We predicted that participants exposed to such cues would affirm their endorsement of prevailing moral norms by expressing greater disapproval of moral (...) transgressions. Participants read brief accounts of two moral violations and rated the moral acceptability of each violation. Violations were more strongly condemned in a condition where participants were exposed to surveillance cues (an image of eyes interposed between the description of the violation and the associated rating scale) than in a control condition (in which the interposed image was of flowers). We discuss the role that public declarations play in the interpersonal evaluation of cooperative dispositions. (shrink)

Most human beliefs are acquired through communication, and so are most misbeliefs. Just like the misbeliefs discussed by McKay & Dennett (M&D), culturally transmitted misbeliefs tend to result from limitations rather than malfunctions of the mechanisms that produce them, and few if any can be argued to be adaptations. However, the mechanisms involved, the contents, and the hypothetical adaptive value tend to be specific to the cultural case.

Von Hippel & Trivers (VH&T) propose that self-deception has evolved to facilitate the deception of others. However, they ignore the subjective moral costs of deception and the crucial issue of credibility in self-deceptive speech. A self-signaling interpretation can account for the ritualistic quality of some self-deceptive affirmations and for the often-noted gap between what self-deceivers say and what they truly believe.

A large amount of research in cognitive psychology is focused on memory distortions, understood as deviations from various (largely implicit) standards. Many alleged distortions actually suggest a highly functional system that balances the cost of acquiring new information with the benefit of relevant, contextually appropriate decision-making. In this sense many memories may be examples of functionally adaptive misbelief.

Inducing religious thoughts increases prosocial behavior among strangers in anonymous contexts. These effects can be explained both by behavioral priming processes as well as by reputational mechanisms. We examine whether belief in moralizing supernatural agents supplies a case for what McKay & Dennett (M&D) call evolved misbelief, concluding that they might be more persuasively seen as an example of culturally evolved misbelief.

The radical evolutionary step that divides human decision-making from that of nonhumans is the ability to excite the reward process for its own sake, in imagination. Combined with hyperbolic over-valuation of the present, this ability is a potential threat to both the individual's long term survival and the natural selection of high intelligence. Human belief is intrinsically or under-founded, which may or may not be adaptive.

I take up the challenge of whyfalsebeliefs are better than “cautious actionpolicies” (target article, sect. 9) in navigating adaptive problems with asymmetric errors. I then suggest that there areinteractionsbetween supernatural beliefs, self-deception, and positive illusions, rendering elements of all such misbeliefs adaptive. Finally, I argue that supernatural beliefs cannot be rejected as adaptive simply because recent experiments are inconclusive. The great costs of religion betray its even greater adaptive benefits – we just have not yet nailed down exactly what they (...) are. (shrink)

McKay & Dennett's (M&D's) description of beliefs, and misbeliefs in particular, is a commendable contribution to the literature; but we argue that referring to beliefs as adaptive or maladaptive can cause conceptual confusion. “Adaptive” is inconsistently defined in the article, which adds to confusion and renders it difficult to evaluate the claims, particularly the possibility of “adaptive misbelief.”.

In his 2012 book Jussim argues that the self-fulfilling prophecy and expectancy effects of descriptive stereotypes are not potent shapers of social reality. However, his conclusion that descriptive stereotypesper sedo not shape social reality is premature and overly reductionist. We review evidence that suggests descriptive stereotypes do have a substantial influence on social reality, by virtue of their influence on collective action.

Boyer & Petersen argue that folk-economic beliefs are widespread – shaped by evolved cognitive systems – and they offer exemplar beliefs to illustrate their thesis. In this commentary, we highlight evidence of substantial variation in one of these exemplars: beliefs about immigration. Contra claims by B&P, we argue that the balance of this evidence suggests the “folk” may actually holdpositivebeliefs about the economic impact of immigration.