J. Intell., Volume 7, Issue 2 (June 2019) – 4 articles

The present study set out to explore the locus of the poorly understood but frequently reported and comparatively large practice effect in sustained attention tests. Drawing on a recently proposed process model of sustained attention tests, several cognitive tasks were administered twice in order to examine which specific component of test performance benefitted from practice and to which extent. It was shown that the tasks representing the three sub-components of sustained attention tests, namely the perception of an item, the simple mental operation to solve an item, and the motor reaction to indicate a response to an item, benefitted from practice. Importantly, the largest practice gain was observed for the task that required item-solving processes in addition to perceptual and motor processes. Two additional postulated mechanisms in sustained attention tests—the deliberate shifting between items and the preprocessing of upcoming items—did not become more efficient through practice. Altogether, the present study shows that the practice effect in sustained attention tests seems to be primarily due to faster item-solving processes and, to a limited extent, due to a faster perception of the item, as well as a faster motor response. Moreover, besides the sub-components, it is likely that also the coordination of perceptual, item-solving, and motor processes benefitted from practice. Altogether, the present paper may have taken a first step towards a better understanding of the specific processes that cause the large practice gains in sustained attention tests. Full article

The aim of this study was to investigate sex similarities and differences in visuospatial and fluid abilities and IQ scores based on those abilities in children aged two to eight. Standardization data from the Snijders-Oomen Nonverbal Intelligence Test for Children aged 2–8 (SON-R 2–8) were used. A representative sample composed of 965 children from the Netherlands and 762 children from Germany was examined. Small but significant mean sex differences favoring girls were observed until age four. At ages six and seven, boys achieved similar cognitive development levels to girls regarding all abilities assessed and outperformed girls on the Mosaics subtest measuring visuospatial cognition. Boys also displayed higher variability rates in performance. The distribution of IQ scores, with the overrepresentation of girls scoring above mean and the overrepresentation of boys scoring below mean in early childhood, altered with age towards parity between the sexes. The results suggest that girls tend to mature earlier with respect to cognitive abilities. During the course of development, however, the differences between girls and boys may become negligible. Full article

In a recent article, Wundrack et al. (2018) put forward an elaborate and intriguing hypothesis on enhanced perspective-taking (Theory of Mind) ability as a consequence of higher personality state variability. While there is evidence in favor of this hypothesis, the clinical examples of bipolar disorder and borderline personality disorder, as highlighted by the authors, demonstrate that a high state variability can also be accompanied by a lower perspective-taking ability (as commonly observed in these disorders). We suggest that only those state changes which are initiated on a voluntary basis and are accompanied by self-awareness go along with a higher perspective-taking ability. Introducing self-awareness as a moderating factor might help explain seemingly conflicting findings related to the hypothesis proposed in the target article. Moreover, we argue that the direction of causality proposed in the target article is not the only conceivable one, and perspective-taking ability could also be a cause, not just a consequence, of personality state variability. Finally, we provide suggestions on how these hypotheses could be tested in future studies. Full article