What are the metacognitive costs of young children's overconfidence?

Children typically hold very optimistic views of their own skills but so far, only a few studies have investigated possible correlates of the ability to predict performance accurately. Therefore, this study examined the role of individual differences in performance estimation accuracy as a global metacognitive index for different monitoring and control skills (item-level judgments of learning [JOLs] and confidence judgments [CJs]), metacognitive control processes (allocation of study time and control of answers), and executive functions (cognitive flexibility, inhibition, working memory) in 6-year-olds (N=93). The three groups of under estimators, realists and over estimators differed significantly in their monitoring and control abilities: the under estimators outperformed the over estimators by showing a higher discrimination in CJs between correct and incorrect recognition. Also, the under estimators scored higher on the adequate control of incorrectly recognized items. Regarding the interplay of monitoring and control processes, under estimators spent more time studying items with low JOLs, and relied more systematically on their monitoring when controlling their recognition compared to over estimators. At the same time, the three groups did not differ significantly from each other in their executive functions. Overall, results indicate that differences in performance estimation accuracy are systematically related to other global and item-level metacognitive monitoring and control abilities in children as young as six years of age, while no meaningful association between performance estimation accuracy and executive functions was found.

Looking too Old? How First Impressions of Older-looking Candidates Contribute to Unfavorable Selection Decisions

Building on theories of impression formation based on faces, this research investigates the impact of job candidates’ facial age appearance on hiring as well as the underlying mechanism. In an experiment, participants decided whether to hire a fictitious candidate aged 50 years, 30 years or without age information. The candidate’s age was signaled either via chronological information (varied by date of birth) or via facial age appearance (varied by a photograph on the résumé). Findings showed that candidates with older-appearing faces—but not chronologically older candidates—triggered impressions of low health and fitness, compared to younger-appearing candidates. These impressions reduced perceptions of person-job fit, which lowered hiring probabilities for older-appearing candidates. These findings provide the first evidence that trait impressions from faces are a determinant of age discrimination in personnel selection. They call for an extension of current models of age discrimination by integrating the effects of face-based trait impressions, particularly with respect to health and fitness.

Differential diagnosis of the honey bee trypanosomatids Crithidia mellificae and Lotmaria passim

Trypanosomatids infecting honey bees have been poorly studied with molecular methods until recently. After the description of Crithidia mellificae (Langridge and McGhee, 1967) it took about forty years until molecular data for honey bee trypanosomatids became available and were used to identify and describe a new trypanosomatid species from honey bees, Lotmaria passim (Evans and Schwarz, 2014). However, an easy method to distinguish them without sequencing is not yet available. Research on the related bumble bee parasites Crithidia bombi and Crithidia expoeki revealed a fragment length polymorphism in the internal transcribed spacer 1 (ITS1), which enabled species discrimination. In search of fragment length polymorphisms for differential diagnostics in honey bee trypanosomatids, we studied honey bee trypanosomatid cell cultures of C. mellificae and L. passim. This research resulted in the identification of fragment length polymorphisms in ITS1 and ITS1-2 markers, which enabled us to develop a diagnostic method to differentiate both honey bee trypanosomatid species without the need for sequencing. However, the amplification success of the ITS1 marker depends probably on the trypanosomatid infection level. Further investigation confirmed that L. passim is the dominant species in Belgium, Japan and Switzerland. We found C. mellificae only rarely in Belgian honey bee samples, but not in honey bee samples from other countries. C. mellificae was also detected in mason bees (Osmia bicornis and Osmia cornuta) besides in honey bees. Further, the characterization and comparison of additional markers from L. passim strain SF (published as C. mellificae strain SF) and a Belgian honey bee sample revealed very low divergence in the 18S rRNA, ITS1-2, 28S rRNA and cytochrome b sequences. Nevertheless, a variable stretch was observed in the gp63 virulence factor.