Suche nach der Ursache des chronischen Ersch?pfungssyndroms

The etiology of chronic fatigue syndrome is subject to a longstanding controversy between scientists, healthcare providers, patients and self-help groups. The reasons for this, sometime heated, dispute are most likely not only due to the diversity and complexity of scientific facts alone but can also be seen as the consequences of the desired legitimation or dreaded delegitimation of the syndrome by the respective etiological model. The mechanisms of these processes will be described one the basis of the current discussion regarding the role of xenotropic murine leukemia virus-related virus in chronic fatigue syndrome.     

Knowing your own mate value: sex-specific personality effects on the accuracy of expected mate choices

Knowing one's mate value (mate-value accuracy) is an important element in reproductive success. We investigated within- and between-sex differences in this ability in a real-life speed-dating event. A total of 190 men and 192 women filled out a personality questionnaire and participated in speed-dating sessions. Immediately after each date, participants recorded who they would choose as mates and who they expected would choose them. In line with evolutionarily informed hypotheses, results indicated that sociosexually unrestricted men and more agreeable women showed greater mate-value accuracy than sociosexually restricted men and less agreeable women, respectively. These results have important implications for understanding mating behavior and perhaps the origin of sex differences in personality.     

Reading development in a tracked school system: A longitudinal study over 3 years using propensity score matching

Background. Assigning students to different school tracks on the basis of their achievement levels is a widely used strategy that aims at giving students the best possible learning opportunity. There is, however, a growing body of literature that questions such positive effects of tracking. Aims. This study compared the developmental trajectories of reading comprehension and decoding speed between students at academic track schools that typically prepare students for university entrance and students at non-academic track schools that usually prepare students for vocational education. Sample. In a longitudinal design with three occasions of data collection, the authors drew on a sample of N= 1,508 5th graders (age at T1 about 11 years, age at T3 about 14 years) from 60 schools in Germany. The academic track sample comprised n= 568 students; the non-academic track sample comprised n= 940 students. Method. Achievement measures were obtained by standardized tests of reading comprehension and decoding speed. Students at the different tracks were closely matched using propensity scores. To compare students’ growth trajectories between the different school tracks, we applied multi-group latent growth curve models. Results. Comparable results were recorded for the complete (unmatched) sample and for the matched pairs. In all cases, students at the different tracks displayed a similar growth in reading comprehension, whereas larger growth rates for students at academic track schools were recorded for decoding speed. Conclusions. Our findings contribute to an increasing body of literature suggesting that tracking might have undesired side effects.     

Neurophysiological preconditions of syntax acquisition

Although the neural network for language processing in the adult brain is well specified, the neural underpinning of language acquisition is still underdetermined. Here, we define the milestones of syntax acquisition and discuss the possible neurophysiological preconditions thereof. Early language learning seems to be based on the bilateral temporal cortices. Subsequent syntax acquisition apparently primarily recruits a neural network involving the left frontal cortex and the temporal cortex connected by a ventrally located fiber system. The late developing ability to comprehend syntactically complex sentences appears to require a neural network that connects Broca’s area to the left posterior temporal cortex via a dorsally located fiber pathway. Thus, acquisition of syntax requires the maturation of fiber bundles connecting the classical language-relevant brain regions.     

Cognitive flexibility as a meta-competency / Flexibilidad cognitiva como meta-competencia

Abstract

There exists a large body of research that has studied cognitive flexibility as an executive function assessed through shifting and set-switching tasks. This approach has been criticized as overly narrow and reductionist, thereby undermining the relevance of cognitive flexibility beyond tightly controlled cognitive tasks. In light of such limitations, we review the extant literature and reflect on the understanding of cognitive flexibility as (1) an cognitive approach to novelty processing and (2) as a conative disposition towards novelty. We present a theoretical model of cognitive flexibility as a meta-competency reflected in adaptive performance which emerges as a strategic response to novelty in dynamic environments. This meta-competency draws on a confluence of cognitive and conative variables that are actively and adaptively harnessed by an individual under specific circumstances.     

Charismatic Leadership and Objective Performance Indicators

Recent empirical and theoretical work has advanced our understanding of charismatic leadership in organisations. Despite this progress, only a few studies have tested the hypothesis that charismatic leadership might be related to objective, organisationally relevant indicators. In order to address this research gap, the present study tested whether charismatic leadership was related to followers’ absenteeism, their training and development activities, as well as branch‐level profit. Charismatic leadership was defined according to Conger and Kanungo's (1998 ) theory. It could be demonstrated that facets of charismatic leadership were negatively related to followers’ absenteeism, but positively related to their training and development activity. Moreover, charismatic leadership showed a positive relationship to profit. In sum, the results contribute to theory and practice of charismatic leadership. Un travail empirique et théorique récent a fait progresser notre compréhension du leadership charismatique dans les organisations. Malgré ce progrès, seules quelques études ont testé l’hypothèse selon laquelle un leadership charismatique serait liéà des facteurs objectifs et pertinents pour l’organisation. Pour une compréhension plus approfondie des effets du leadership chatismatique, la présente étude teste si ce style de leadership est lié aux suiveurs, à l’absentéisme, aux activités de formation et de développement ainsi qu’aux bénéfices au niveau de la branche. Le leadership charismatique est défini en accord avec la théorie de Conger et Kanungo (1998). On a pu démontrer que les facettes du leadership charismatique sont liées négativement aux suiveurs, à l’absentéisme et positivement à l’activité de formation et de dévelpppement. En outre, le leadership charismatique montre une relation positive au profit. En somme, les résultats contribuent à la théorie et à la pratique du leadership charismatique.