On Merely Modal Epistemic Peers: Challenging the Equal-Weight View

There is a controversy, within social epistemology, over how to handle disagreement among epistemic peers. Call this the problem of peer disagreement. There is a solution, i.e. the equal-weight view, which says that disagreement among epistemic peers is a reason for each peer to lower the credence they place in their respective positions. However, this solution is susceptible to a serious challenge. Call it the merely modal peers challenge. Throughout parts of modal space, which resemble the actual world almost completely, there are hordes of epistemic peers, who disagree with almost any arbitrarily chosen belief had by residents of the actual world. Further, the mere modality of these peers is not itself an epistemic difference-maker. Thus, on the equal-weight view, we should significantly lower the credence we place in most of our beliefs. Surely, this is seriously mistaken. Thus, there are serious considerations that cut against the equal-weight view.     

How do slender mineral crystals resist buckling in biological materials?

Mineral crystals in biological materials such as bone, tooth, and sea shell are susceptible to buckling under compressive loading due to their slender geometry with large aspect ratios. How does nature deal with this problem? This question is especially interesting in view of the three orders of magnitude difference in elastic modulus between protein and mineral. As a first analysis of this question, we study the stability of a single mineral platelet confined in an otherwise perfect protein–mineral nanostructure. We find that there exists a transition of buckling strength from an aspect ratio-dependent regime to a lower threshold value, independent of the crystal geometry. Typical values of the aspect ratio of mineral crystals of bone and nacre fall in this transition region. The existence of a buckling strength independent of the detailed geometrical parameters of mineral may be critically important from the point of view of structure robustness as the composite behaviour of biomaterials should not depend sensitively on small variations in crystal size and shape.     

A dual process item response theory model for polytomous multidimensional forced-choice items

The use of multidimensional forced-choice (MFC) items to assess non-cognitive traits such as personality, interests and values in psychological tests has a long history, because MFC items show strengths in preventing response bias. Recently, there has been a surge of interest in developing item response theory (IRT) models for MFC items. However, nearly all of the existing IRT models have been developed for MFC items with binary scores. Real tests use MFC items with more than two categories; such items are more informative than their binary counterparts. This study developed a new IRT model for polytomous MFC items based on the cognitive model of choice, which describes the cognitive processes underlying humans' preferential choice behaviours. The new model is unique in its ability to account for the ipsative nature of polytomous MFC items, to assess individual psychological differentiation in interests, values and emotions, and to compare the differentiation levels of latent traits between individuals. Simulation studies were conducted to examine the parameter recovery of the new model with existing computer programs. The results showed that both statement parameters and person parameters were well recovered when the sample size was sufficient. The more complete the linking of the statements was, the more accurate the parameter estimation was. This paper provides an empirical example of a career interest test using four-category MFC items. Although some aspects of the model (e.g., the nature of the person parameters) require additional validation, our approach appears promising.     

A comparative study of personality in adults and children: Hong Kong vs England

The 90-item adult version of the Eysenck Personality Questionnaire was translated into Chinese and administered to 270 male and 462 female subjects in Hong Kong. In a second study the 81-item version of the Junior EPQ (JEPQ) was translated into Chinese and given to 698 boys and 629 girls.Reasonably valid scales for use in Hong Kong are suggested for both adult and junior forms of the questionnaire. In a direct comparison of British and Chinese (Hong Kong) groups, using reduced scales comprising only items both scoring keys had in common. Hong Kong adults scored higher on Psychoticism and Social Desirability and lower on Extraversion than the British while children from Hong Kong scored lower on Extraversion and Neuroticism but higher on Social Desirability than their British counterparts. Indices of factor comparison were universally high, indicating that the major dimensions of personality were very similar in Hong Kong Chinese as in British subjects.     

Balancing fit and parsimony to improve Q-matrix validation

The Q-matrix identifies the subset of attributes measured by each item in the cognitive diagnosis modelling framework. Usually constructed by domain experts, the Q-matrix might contain some misspecifications, disrupting classification accuracy. Empirical Q-matrix validation methods such as the general discrimination index (GDI) and Wald have shown promising results in addressing this problem. However, a cut-off point is used in both methods, which might be suboptimal. To address this limitation, the Hull method is proposed and evaluated in the present study. This method aims to find the optimal balance between fit and parsimony, and it is flexible enough to be used either with a measure of item discrimination (the proportion of variance accounted for, PVAF) or a coefficient of determination (pseudo-R²). Results from a simulation study showed that the Hull method consistently showed the best performance and shortest computation time, especially when used with the PVAF. The Wald method also performed very well overall, while the GDI method obtained poor results when the number of attributes was high. The absence of a cut-off point provides greater flexibility to the Hull method, and it places it as a comprehensive solution to the Q-matrix specification problem in applied settings. This proposal is illustrated using real data.     

Exposure to sexism can decrease implicit gender stereotype bias

Two studies examined the effect of exposure to sexism on implicit gender bias, focusing specifically on stereotypes of men as competent and women as warm. Male and female participants were exposed to sexism or no sexism. In both Experiment 1 (Implicit Association Task; N = 115) and Experiment 2 (Go/No‐go Association Task; N = 167), women who had been exposed to sexist beliefs demonstrated less implicit gender stereotype bias relative to women who were not exposed to sexism. In contrast, exposure to sexism did not influence men's implicit gender stereotype bias. In Experiment 2, process modelling revealed that women's reduction in bias in response to sexism was related to increased accuracy orientation and a tendency to make warmth versus competence judgments. The implications of these findings for current understandings of sexism and its effects on gender stereotypes are discussed.     

Does a pear growl? Interference from semantic properties of orthographic neighbors

In this study, we investigated whether semantic properties of a word’s orthographic neighbors are activated during visual word recognition. In two experiments, words were presented with a property that was not true for the word itself. We manipulated whether the property was true for an orthographic neighbor of the word. Our results showed that rejection of the property was slower and less accurate when the property was true for a neighbor than when the property was not true for a neighbor. These findings indicate that semantic information is activated before orthographic processing is finished. The present results are problematic for the links model (Forster, 2006; Forster & Hector, 2002) that was recently proposed in order to bring form-first models of visual word recognition into line with previously reported findings (Forster & Hector, 2002; Pecher, Zeelenberg, & Wagenmakers, 2005; Rodd, 2004).     

Modest meta‐philosophical skepticism

Intractable disagreement among philosophers is ubiquitous. An implication of such disagreement is that many philosophers hold false philosophical beliefs (i.e. at most only one party to a dispute can be right). Suppose that we distribute philosophers along a spectrum arranged from philosophers with mostly true philosophical beliefs on one end (high‐reliability), to those with mostly false philosophical beliefs on the other (low‐reliability), and everyone else somewhere in‐between (call this is the reliability spectrum). It is hard to see how philosophers could accurately locate themselves on the reliability spectrum; they are prima facie as well positioned as their peers with respect to philosophical matters (call this the placement problem). In this paper, I argue that the reliability spectrum and placement problem lend support to modest meta‐philosophical skepticism: we have a pro tanto (but not an all‐things‐considered) reason to withhold ascent to philosophical claims.     

Optimism and well-being: a prospective multi-method and multi-dimensional examination of optimism as a resilience factor following the occurrence of stressful life events

Optimism has been conceptualised variously as positive expectations (PE) for the future , optimistic attributions , illusion of control , and self-enhancing biases. Relatively little research has examined these multiple dimensions of optimism in relation to psychological and physical health. The current study assessed the multi-dimensional nature of optimism within a prospective vulnerability-stress framework. Initial principal component analyses revealed the following dimensions: PEs, Inferential Style (IS), Sense of Invulnerability (SI), and Overconfidence (O). Prospective follow-up analyses demonstrated that PE was associated with fewer depressive episodes and moderated the effect of stressful life events on depressive symptoms. SI also moderated the effect of life stress on anxiety symptoms. Generally, our findings indicated that optimism is a multifaceted construct and not all forms of optimism have the same effects on well-being. Specifically, our findings indicted that PE may be the most relevant to depression, whereas SI may be the most relevant to anxiety.