Similarity semantics and minimal changes of belief

Different similarity relations on sets are introduced, and their logical properties are investigated. Close relationships are shown to hold between similarity relations that are based on symmetrical difference and operators of belief contraction that are based on relational selection functions. Two new rationality criteria for minimal belief contraction, the maximizing property and the reducing property, are proposed.     

Sexual Debut Ages in Heterosexual,Lesbian, Gay,and Bisexual Young Adults in Norway

This study estimates sexual debut ages in young heterosexual, lesbian, gay, and bisexual men and women in Norway. A questionnaire survey was completed online by 27.2 % of a representative national web sample of 2090 persons aged 18–29 years. Three self-selected samples of 924 respondents completed an extended version of the survey online. Lesbian and bisexual women reported earlier experience of orgasm through masturbation than heterosexual women (median 13.1 vs. 15.2 years), and heterosexual men (median 13.5) reported earlier debut than heterosexual women. There was a statistically significant difference between heterosexual and lesbian and bisexual women’s age at the first experience of receptive vaginal sex (median 16.8 vs. 15.4 years). As regards experience of insertive vaginal sex, a significantly higher percentage of heterosexual men than women, and of heterosexual and lesbian and bisexual women, reported experience. It was more common among lesbian and bisexual women than heterosexual women to have had oral sex with another woman, but in neither group did the cumulative percent reach 50 % by the age of 29 years and the median could not be estimated. Gay and bisexual men reported earlier receptive anal sex debut than heterosexual men. With regard to insertive anal sex, gay and bisexual men accumulated experience earlier than heterosexual men, and lesbian and bisexual women acquired this experience earlier than heterosexual women. Compared to heterosexuals, LGB persons of both genders engage in more varied sexual activities. Lesbian and gay persons have same-sex experiences at an earlier age than bisexuals.     

Revisiting the mediating role of leader–member exchange in transformational leadership: the differential impact model

Transformational leadership (TFL) has been proposed as an essential antecedent of leader–member exchange (LMX), which in turn affects outcomes in organizations. We extend this mediation hypothesis in two ways by proposing a differential impact model, which we test on three organizational outcomes: employee job satisfaction, employee organizational commitment, and leader effectiveness. First, we extend LMX’s mediational impact—which has previously only been tested for employee outcomes—to leader effectiveness. Second, we argue that this mediation will be stronger for outcomes that are more proximal rather than distal to dyadic relations between leader and followers (high proximity: job satisfaction; medium proximity: organizational commitment; low proximity: leader effectiveness). Meta-analytic structural equation modelling based on 132 studies revealed that LMX mediates TFL’s relationships with employee outcomes (more strongly for job satisfaction than for commitment), but not with leader effectiveness, whereas TFL showed a stronger direct link to leader effectiveness. The findings suggest that TLF and LMX contribute differentially to organizational outcomes depending on their proximity to dyadic relations between leaders and followers. The differential impact model uncovers leadership effectiveness processes, integrates influential leadership theories, and highlights the importance of distinguishing between different outcome measures and the processes facilitating them.     

Speech segmentation by statistical learning is supported by domain-general processes within working memory

The purpose of this study was to examine the extent to which working memory resources are recruited during statistical learning (SL). Participants were asked to identify novel words in an artificial speech stream where the transitional probabilities between syllables provided the only segmentation cue. Experiments 1 and 2 demonstrated that segmentation performance improved when the speech rate was slowed down, suggesting that SL is supported by some form of active processing or maintenance mechanism that operates more effectively under slower presentation rates. In Experiment 3 we investigated the nature of this mechanism by asking participants to perform a two-back task while listening to the speech stream. Half of the participants performed a two-back rhyme task designed to engage phonological processing, whereas the other half performed a comparable two-back task on un-nameable visual shapes. It was hypothesized that if SL is dependent only upon domain-specific processes (i.e., phonological rehearsal), the rhyme task should impair speech segmentation performance more than the shape task. However, the two loads were equally disruptive to learning, as they both eradicated the benefit provided by the slow rate. These results suggest that SL is supported by working-memory processes that rely on domain-general resources.     

Reaching Wuthering Heights with Brave New Words: The Influence of Originality of Words on the Success of Outstanding Best‐Sellers

The judgment and ultimately the success of creative products should be determined by their properties. However, it has not been considered so far whether the same applies to books. Earlier research has found an inverted‐U relationship between originality of stimuli and their success. Linguistic originality as a text feature could influence the success of books as creative products in a natural experiment. The present historiometric study investigated whether originality predicts the popularity in a significant sample, the most best‐selling English books from 200 years. Originality was calculated based on word frequency using a commercial service. Popularity was assessed with a composite measure including indicators like number of sold copies. Regression analysis indicated originality had a direct linear effect on popularity, partially moderated by the time of first publishing. That is, while originality was generally beneficial for the success of a best‐seller, the same originality was more appreciated at a later point in time. This is the first quantitative study supporting the long‐held assumption that the evaluation of creative narratives is influenced by temporal context. The fact that some works like The Great Gatsby got more appreciation when they were rediscovered may reflect a general principle rather than mere exceptions.     

Medical knowledge in a social world: Introduction to the special issue

Philosophy of medicine has traditionally examined two issues: the scientific ontology for medicine and the epistemic significance of the types of evidence used in medical research. In answering each question, philosophers have typically brought to bear tools from traditional analytic philosophy. In contrast, this volume explores medical knowledge from the perspective offered by social epistemology. While many of the same issues are addressed, the approach to these issues generates both fresh questions and new insights into old debates. In addition, the broader purview offered by social epistemology opens up opportunities to address new topics such as the role of consensus conferences, epistemic injustice, the value of medical knowledge, continuing medical education, and industry funding. This article situates and summarizes the contributions to this special issue.

     

Setting and changing feature priorities in visual short-term memory

Many everyday tasks require prioritizing some visual features over competing ones, both during the selection from the rich sensory input and while maintaining information in visual short-term memory (VSTM). Here, we show that observers can change priorities in VSTM when, initially, they attended to a different feature. Observers reported from memory the orientation of one of two spatially interspersed groups of black and white gratings. Using colored pre-cues (presented before stimulus onset) and retro-cues (presented after stimulus offset) predicting the to-be-reported group, we manipulated observers’ feature priorities independently during stimulus encoding and maintenance, respectively. Valid pre-cues reliably increased observers’ performance (reduced guessing, increased report precision) as compared to neutral ones; invalid pre-cues had the opposite effect. Valid retro-cues also consistently improved performance (by reducing random guesses), even if the unexpected group suddenly became relevant (invalid-valid condition). Thus, feature-based attention can reshape priorities in VSTM protecting information that would otherwise be forgotten.     

Personality Traits Predict Smartphone Usage

The present study investigates to what degree individual differences can predict frequency and duration of actual behaviour, manifested in mobile application (app) usage on smartphones. In particular, this work focuses on the identification of stable associations between personality on the factor and facet level, fluid intelligence, demography and app usage in 16 distinct categories. A total of 137 subjects (87 women and 50 men), with an average age of 24 (SD = 4.72), participated in a 90‐min psychometric lab session as well as in a subsequent 60‐day data logging study in the field. Our data suggest that personality traits predict mobile application usage in several specific categories such as communication, photography, gaming, transportation and entertainment. Extraversion, conscientiousness and agreeableness are better predictors of mobile application usage than basic demographic variables in several distinct categories. Furthermore, predictive performance is slightly higher for single factor—in comparison with facet‐level personality scores. Fluid intelligence and demographics additionally show stable associations with categorical app usage. In sum, this study demonstrates how individual differences can be effectively related to actual behaviour and how this can assist in understanding the behavioural underpinnings of personality. Copyright © 2017 European Association of Personality Psychology