Associative memory or algorithmic search: a comparative study on learning strategies of bats and shrews

Two common strategies for successful foraging are learning to associate specific sensory cues with patches of prey ("associative learning") and using set decision-making rules to systematically scan for prey ("algorithmic search"). We investigated whether an animal's life history affects which of these two foraging strategies it is likely to use. Natterer's bats (Myotis nattereri) have slow life-history traits and we predicted they would be more likely to use associative learning. Common shrews (Sorex araneus) have fast life-history traits and we predicted that they would rely more heavily on routine-based search. Apart from their marked differences in life-history traits, these two mammals are similar in body size, brain weight, habitat, and diet. We assessed foraging strategy, associative learning ability, and retention time with a four-arm maze; one arm contained a food reward and was marked with four sensory stimuli. Bats and shrews differed significantly in their foraging strategies. Most bats learned to associate the sensory stimuli with the reward and remembered this association over time. Most shrews searched the maze using consistent decision-making rules, but did not learn or remember the association. We discuss these results in terms of life-history traits and other key differences between these species. Our results suggest a link between an animal's life-history strategy and its use of associative learning.     

Straightening priority out

In recent work, Louis deRosset (Philosophical Studies 149:73?C97, 2010) has argued that priority theorists, who hold that truths about macroscopic objects can be metaphysically explained without reference to such things, cannot meet an independently motivated constraint upon good explanation. By clarifying the nature of the priority theorist??s project, I argue that deRosset??s argument fails to establish its conclusion.     

Stereotype threat: Antecedents and consequences for working women

Three studies investigated antecedents and consequences of stereotype threat for female employees. The results of Studies 1 and 2 suggest that social comparisons with men are associated with feelings of stereotype threat whereas social comparisons with women are not. Stereotype threat, in turn, was associated with conflict surrounding women's identity as female employees and with decreased perceived likelihood of achieving career goals. Study 3 extended these findings by demonstrating that feelings of stereotype threat are also negatively related to workplace attitudes and turnover intentions. Furthermore, the effect of stereotype threat on these job attitudes and intentions was itself mediated by identity conflict and perceived likelihood of achieving career goals. Implications and limitations of these findings are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

The evolution and psychology of self-deception

In this article we argue that self-deception evolved to facilitate interpersonal deception by allowing people to avoid the cues to conscious deception that might reveal deceptive intent. Self-deception has two additional advantages: It eliminates the costly cognitive load that is typically associated with deceiving, and it can minimize retribution if the deception is discovered. Beyond its role in specific acts of deception, self-deceptive self-enhancement also allows people to display more confidence than is warranted, which has a host of social advantages. The question then arises of how the self can be both deceiver and deceived. We propose that this is achieved through dissociations of mental processes, including conscious versus unconscious memories, conscious versus unconscious attitudes, and automatic versus controlled processes. Given the variety of methods for deceiving others, it should come as no surprise that self-deception manifests itself in a number of different psychological processes, and we discuss various types of self-deception. We then discuss the interpersonal versus intrapersonal nature of self-deception before considering the levels of consciousness at which the self can be deceived. Finally, we contrast our evolutionary approach to self-deception with current theories and debates in psychology and consider some of the costs associated with self-deception.     

Behandlungs- und Kunstfehler in der Psychoanalyse

Failures and transgressions in psychoanalyses are nowadays more often published and also ascribed to mistakes made by the therapists. In German professional literature, however, no difference is made between treatment errors due to the special method and serious malpractice. The authors show in case studies transgressions in the psychoanalytic setting und discuss their causes and consequences.     

Social Capital and Individual Happiness in Europe

This paper explores the relationship between social capital and happiness both in Europe as a whole, as well as in its four main geographical macro-regions—North, South, East and West—separately. We test the hypothesis of whether social capital, in its three-fold definition established by Coleman (Am J Sociol 94:S95–S120 1988)—trust, social interaction, and norms and sanctions—influences individual happiness across European countries and regions. The concept of social capital is further enriched by incorporating Putnam (Making democracy work—civic traditions in modern Italy. Princeton University Press, Princeton, 1993) and Olson (The rise and decline of nations—economic growth, stagflation, and social rigidities. Yale University Press, New Haven and London, 1982) type variables on associational activity. Using ordinal logistic regression analysis on data for 48,583 individuals from 25 European countries, we reach three main findings. First, social capital matters for happiness across the three dimensions considered. Second, the main drivers of the effects of social capital on happiness appear to be informal social interaction and general social, as well as institutional trust. And third, there are significant differences in how social capital interacts with happiness across different areas of Europe, with the connection being at is weakest in the Nordic countries.     

Efficient Hessian computation using sparse matrix derivatives in RAM notation

This article proposes a new, more efficient method to compute the minus two log likelihood, its gradient, and the Hessian for structural equation models (SEMs) in reticular action model (RAM) notation. The method exploits the beneficial aspect of RAM notation that the matrix derivatives used in RAM are sparse. For an SEM with K variables, P parameters, and P′ entries in the symmetrical or asymmetrical matrix of the RAM notation filled with parameters, the asymptotical run time of the algorithm is O(P?′?K ²?+?P ² K ²?+?K ³). The naive implementation and numerical implementations are both O(P ² K ³), so that for typical applications of SEM, the proposed algorithm is asymptotically K times faster than the best previously known algorithm. A simulation comparison with a numerical algorithm shows that the asymptotical efficiency is transferred to an applied computational advantage that is crucial for the application of maximum likelihood estimation, even in small, but especially in moderate or large, SEMs.     

Reading about explanations enhances perceptions of inevitability and foreseeability: a cross-cultural study with Wikipedia articles

In hindsight, people often perceive events to be more inevitable and foreseeable than in foresight. According to Causal Model Theory (Nestler et al. in J Exp Psychol Learn Mem Cogn 34: 1043–1054, 2008), causal explanations are crucial for such hindsight distortions to occur. The present study provides further empirical support for this notion but extends previous findings in several ways. First, ecologically valid materials were used. Second, the effect of causal information on hindsight distortions was investigated in the realm of previously known events. Third, cross-cultural differences in reasoning (analytic vs. holistic) were taken into account. Specifically, German and Vietnamese participants in our study were presented with Wikipedia articles about the nuclear power plant in Fukushima Daiichi, Japan. They read either the version that existed before the nuclear disaster unfolded (Version 1) or the article that existed 8 weeks after the catastrophe commenced (Version 2). Only the latter contained elaborations on causal antecedents and therefore provided an explanation for the disaster. Reading that version led participants to perceive the nuclear disaster to be more likely inevitable and foreseeable when compared to reading Version 1. Cultural background did not exert a significant effect on these perceptions. Hence, hindsight distortions were obtained for ecologically valid materials even if the event was already known. Implications and directions for future research are discussed.     

Couples' evaluations of fatherhood in different stages of the family life cycle

Fathers' and mothers' views on mothers' satisfaction with paternal behaviour as well as the respective processes of origination were studied in 393 cohabiting couples from three different stages of the family life cycle. Data on paternal competence and the couples' relationship characteristics were included as predictors in multiple regression analyses, and the stages of the family life cycle were taken into account with multigroup regression analyses. Results showed that the mothers were more satisfied with paternal behaviour than the fathers thought the mothers were. Moreover, mothers were satisfied when the fathers were willing to spend time with the child, whereas fathers thought that their partners were satisfied when they were able to establish and maintain a relationship with the child. Couple relationship satisfaction had a consistent impact on fathers' views, whereas it was not relevant to mothers' views unless the oldest child had reached adolescence.