Using Latent Class Analysis to Model Temperament Types

Mixture models are appropriate for data that arise from a set of qualitatively different subpopulations. In this study, latent class analysis was applied to observational data from a laboratory assessment of infant temperament at four months of age. The EM algorithm was used to fit the models, and the Bayesian method of posterior predictive checks was used for model selection. Results show at least three types of infant temperament, with patterns consistent with those identified by previous researchers who classified the infants using a theoretically based system. Multiple imputation of group memberships is proposed as an alternative to assigning subjects to the latent class with maximum posterior probability in order to reflect variance due to uncertainty in the parameter estimation. Latent class membership at four months of age predicted longitudinal outcomes at four years of age. The example illustrates issues relevant to all mixture models, including estimation, multi-modality, model selection, and comparisons based on the latent group indicators.     

Correlations, deviations and expectations: the Extended Principle of the Common Cause

The Principle of the Common Cause is usually understood to provide causal explanations for probabilistic correlations obtaining between causally unrelated events. In this study, an extended interpretation of the principle is proposed, according to which common causes should be invoked to explain positive correlations whose values depart from the ones that one would expect to obtain in accordance to her probabilistic expectations. In addition, a probabilistic model for common causes is tailored which satisfies the generalized version of the principle, at the same time including the standard conjunctive-fork model as a special case.     

Emergent Literacy and Early Writing Skills

In the present study, the authors aimed to assess the short- and long-term predictive power of the various components of an emergent literacy model on early writing abilities in a language with a mainly transparent orthography (Italian). Emergent literacy skills were assessed in 72 children (M age = 5.05 years, SD = ± .03) who were followed longitudinally from preschool to the end of the first grade of primary school. Their early writing abilities (orthographic correctness in writing individual words) and their advanced writing abilities (orthographic correctness in text writing) were tested at the beginning and at the end of the school year. Multiple stepwise and logistic regression analyses were conducted to evaluate the predictive capacities of emergent literacy abilities on early and advanced writing competences. Results show that notational competence is a strong predictor of early writing skills and that phonological competence only has an effect insofar as it is integrated with notational competence. Emergent literacy competences do not significantly predict orthographic errors in advanced text writing. This research allows for reconsideration of the importance of phonological awareness and gives a central role to notational competence in predicting early writing competence.     

Stability and Change of Ego Resiliency From Late Adolescence to Young Adulthood: A Multiperspective Study Using the ER89–R Scale

In this research, we examined the psychometric properties of the Revised Ego Resiliency 89 Scale (ER89–R; Alessandri, Vecchio, Steca, Caprara, & Caprara, 2008), a brief self-report measure of ego resiliency. The scale has been used to assess the development of ego resiliency from late adolescence to emerging adulthood, focusing on different ways to define continuity and change. We analyzed longitudinal self-report data from 267 late adolescents (44% male) using 4 different approaches: factor analysis for testing construct continuity, correlational analysis for examining differential stability, latent growth modeling for analyzing mean level change, and the reliable change index for studying the occurrence of change at the individual level. Converging evidence points to the marked stability of ego resiliency from 16 to 20 years, both for males and females. The scale predicts externalizing and internalizing problems, both concurrently and at 2 and 4 years of distance. Findings suggest that the ER89–R scale represents a valid and reliable instrument that can be fruitfully suited for studying ego resiliency through various developmental stages.     

Effects of MK-801 and ethanol combinations on memory consolidation in CD1 mice: involvement of GABAergic mechanisms

In the present research the effect of the noncompetitive N-methyl-d-aspartate receptor antagonist MK-801 and ethanol combinations on memory consolidation and the involvement of GABAergic mechanisms in this effect were investigated in CD1 mice injected intraperitoneally with the drugs immediately or 120 min after training in a one-trial inhibitory avoidance apparatus and tested for retention 24 h later. The results showed that (a) the retention performances of mice were impaired in a dose-dependent manner by immediate posttraining MK-801 (0.2 and 0.3, but not 0.1 mg/kg) and ethanol (1 and 2, but not 0.5 g/kg) administrations; (b) an otherwise ineffective dose of MK-801 (0.1 mg/kg) enhanced the deleterious effect exerted by ethanol (1 and 2 g/kg); (c) an otherwise ineffective dose of muscimol (0.5 mg/kg) enhanced, while otherwise ineffective doses of picrotoxin (0.25 mg/kg) or bicuculline (0.1 mg/kg) antagonized, this effect; and (d) no effect was observed when the treatments were carried out 120 min after training, suggesting that the effects observed following immediate posttraining administrations were due to the influence on the consolidation of memory. From these experiments it is evident that (a) MK-801 enhances ethanol's effects on memory consolidation and (b) GABAergic mechanisms are involved in this effect.     

Higher-order factors of the big five and basic values: empirical and theoretical relations

The Big Five Model of personality and Schwartz's theory of basic values are two prominent taxonomies that offer a convenient way to organize the major individual differences in, respectively, personality traits and personal values. Both taxonomies provide a hierarchical framework, whose components can be traced back to a smaller number of broader dimensions. The current study investigated the relationship between the two superordinate factors of personality encompassing the Big Five dimensions (alpha and beta) and the four higher-level value types from Schwartz's theory (Self-transcendence, Self-enhancement, Conservation, and Openness to change). To examine the relations between higher-order traits and values, we relied on factor analysis and multidimensional scaling. Results indicated that alpha and beta were differently related to the Conservation versus Openness to change dimension. Alpha was positively related to values that emphasize protecting stability and respecting norms and traditions, and negatively related to values emphasizing receptiveness to change and independence of thought, feeling, and action. The opposite pattern of relations was found for beta.     

Epistemic closure, skepticism and defeasibility

Those of us who have followed Fred Dretske??s lead with regard to epistemic closure and its impact on skepticism have been half-wrong for the last four decades. But those who have opposed our Dretskean stance, contextualists in particular, have been just wrong. We have been half-right. Dretske rightly claimed that epistemic status is not closed under logical implication. Unlike the Dretskean cases, the new counterexamples to closure offered here render every form of contextualist pro-closure maneuvering useless. But there is a way of going wrong under Dretske??s lead. As the paper argues, Cartesian skepticism thrives on closure failure in a way that is yet to be acknowledged in the literature. The skeptic can make do with principles which are weaker than the familiar closure principles. But I will further claim that this is only a momentary reprieve for the skeptic. As it turns out, one of the weaker principles on which a skeptical modus tollens must rest can be shown false.     

Cultural intelligence is key to explaining human tool use

Contrary to Vaesen, we argue that a small number of key traits are sufficient to explain modern human tool use. Here we outline and defend the cultural intelligence (CI) hypothesis. In doing so, we critically re-examine the role of social transmission in explaining human tool use.     

Punishing for your own good: the case of reputation-based cooperation

Contrary to Guala, I claim that several mechanisms can explain punishment in humans. Here I focus on reputation-based cooperation--and I explore how it can lead to punishment under situations that may or may not be perceived as being anonymous. Additionally, no particular mechanism stands out in predicting an excess of punishment under constrained lab conditions.