Left-handedness in twin families: support of an environmental hypothesis

Information on handedness, assessed as writing-hand, was collected from 197 MZ twin pairs and 203 DZ twin pairs and from their parents, spouses, and children. Associations for pairs of relatives were studied by 2 X 2 tables, computing chi squared-values and tetrachoric correlations. Correlations of about .3 were obtained for mother-offspring and sibling pairs, while for cousins the correlation was .25 (in a small sample). No other significant associations were found, not even for twins. These results suggest only a small, if any, genetic effect, and only a small environmental between family effect, most of which seems to be a maternal effect. The lack of cotwin correlations and correlations for one of the twins with her/his ordinary brothers/sisters suggest the existence of an effect specific to twins, since the correlation for pairs of ordinary siblings is significant. Conclusions drawn from twin studies alone may be biased. The frequency of left-hand writers has increased from 1% to 10% in the different age groups born during the last century in Norway. This age effect is present mainly in hand writing and not so much in handedness generally, suggesting a decrease in cultural repression against left-hand writing.     

Enhanced right hemisphere activation in the mathematically precocious: A preliminary EEG investigation

A preliminary electroencephalographic (EEG) investigation was conducted to determine if the pattern of hemispheric activation in mathematically precocious youth differs from that of average math ability subjects. Alpha activity at four brain sites (frontal, temporal, parietal, and occipital lobes) over the left and right cerebral hemispheres (LH/RH) was monitored while 12- to 14-year-old, right-handed males: (a) looked at a blank slide (baseline condition), (b) judged which of two chimeric faces was "happier," and (c) determined if a word was a noun or a verb. At baseline, the LH of the precocious group was found to be more active at all four brain sites relative to that of the average ability group. During chimeric face processing, the gifted subjects exhibited a significant reduction in alpha power over the RH, primarily at the temporal lobe, while no such alpha suppression was observed in the average ability subjects. For noun/verb determinations, no significant alpha power reductions were obtained for either group. These electrophysiological data generally corroborate the behavioral findings of O'Boyle and Benbow (1990a) and support their contention that enhanced RH involvement during cognitive processing may be a correlate of mathematical precocity. Moreover, the pattern of activation observed across tasks suggests that the ability to effectively coordinate LH and RH processing resources at an early age may be linked to intellectual giftedness.     

Factorial structure and invariance across gender of the Swedish self-consciousness scale

In this study, I tested different factor models and the factorial invariance across gender for the Self-Consciousness Scale (Fenigstein, Scheier, & Buss (1975) using confirmatory factor analyses. University students (251 women and 259 men) completed the Swedish version of the scale. A respecified (Item 15 loading on the factor Internal State Awareness [ISA] instead of on the factor Self-Reflection [SR]) 17-item, 4-factor model of Burnkrant and Page (1984) including the factors SR, ISA, Public Self-Consciousness, and Social Anxiety demonstrated the best fit for both men and women. Factor intercorrelations were overall stronger for women. The respecified model demonstrated factorial invariance across gender. I discuss the strengthening of scale reliability through the expansion of subscale items and invariance testing across groups.     

The relationship between performance-based self-esteem and self-reported work and health behaviors among Danish knowledge workers

Since knowledge intensive work often requires self-management, one might fear that persons who are dependent on work success for self-esteem will have difficulties in finding a healthful and sustainable balance between internal needs and external demands. Accordingly, we examined to what degree work-related performance-based self-esteem (PBS) was linked to work and health behaviors in 392 knowledge workers (226 women, 166 men). In the women group, multiple binary logistic regression analyses with repeated measurements showed that the PBS score was associated with 10 of the 17 examined work and health behaviors. For men the corresponding figure was 3 of 17. In both men and women, higher PBS scores were positively associated with reports of efforts and strivings for work as well as attending work while ill. In conclusion, statistically significant relationships between PBS and work and health behaviors were more clearly visible among women than men. Whether this gender difference is dependent on the study design, or on true inherent differences between women and men, cannot be concluded with any certainty. However, persons who described themselves as being relatively more dependent on work accomplishments for a high self-esteem, as expressed by the PBS score, seem to display work behaviors that may lessen their restitution time. In addition, they also seem to be more prone to work while sick.     

Is there evidence for the use of art therapy in treatment of psychosomatic disorders,eating disorders and crisis? A comparative study of two different systems for evaluation

A comparative study of two different systems for evaluation. Scandinavian Journal of Psychology 53, 47-53. As with any type of treatment the requirement for evidence based practice (EBP) has also affected art therapy (AT) when used as an intervention. This review evaluates the available evidence for using AT for psychosomatic disorders, eating disorders and crisis. The search in Cochrane, Best Practice, AMED, CINAHL, PION, PsycINFO and PubMed from 1987 until now resulted in a huge number of articles but only 32 articles met our criteria for evaluations. The articles were assessed with two evaluation systems, the GRADE system used by the Swedish Council on Health Technology Assessment (SBU) and the US Preventive Services Task Force (USPSTF/Task Force). When comparing the results we found that the GRADE evaluation system rejected the quality in 84% of the 32 studies and the USPSTF/Task Force 41% of these studies. An evidence base for AT was found only according to the criteria of USPSTF/Task Force. Hence, the evidence concept is not explicit, which means that effective treatments run a risk of not being implemented in health care. We suggest a broader view of what constitutes evidence in order to make it possible to include different types of research designs and methods.     

Using individual differences to predict job performance: correcting for direct and indirect restriction of range

The present study investigates the relationship between individual differences, indicated by personality (FFM) and general mental ability (GMA), and job performance applying two different methods of correction for range restriction. The results, derived by analyzing meta-analytic correlations, show that the more accurate method of correcting for indirect range restriction increased the operational validity of individual differences in predicting job performance and that this increase primarily was due to general mental ability being a stronger predictor than any of the personality traits. The estimates for single traits can be applied in practice to maximize prediction of job performance. Further, differences in the relative importance of general mental ability in relation to overall personality assessment methods was substantive and the estimates provided enables practitioners to perform a correct utility analysis of their overall selection procedure.     

Criterion Validity is Maintained When Items are Evaluatively Neutralized: Evidence from a Full‐scale Five‐factor Model Inventory

The original version and an evaluatively neutralized version (with items rephrased to reduce popularity) of a personality inventory were compared. The results revealed (i) similar criterion validity across three different sets of self‐rated behaviours, (ii) stronger relations to the rated social desirability of criteria for the original version and (iii) less correlation between factors for the neutralized version. We take the results to indicate that evaluative neutralization is a viable technique for reducing social desirability in self‐ratings. Implications for test construction are discussed. Copyright © 2014 European Association of Personality Psychology     

Age differences in the neural response to emotional distraction during working memory encoding

Age-related declines in attention and working memory (WM) are well documented and may be worsened by the occurrence of distracting information. Emotionally valenced stimuli may have particularly strong distracting effects on cognition. We investigated age-related differences in emotional distraction using task-fMRI. WM performance in older adults was lower for emotional compared with neutral distractors, suggesting a disproportional impairment elicited by emotional task-irrelevant information. Critically, older adults were particularly distracted by task-irrelevant positive information, whereas the opposite pattern was found for younger adults. Age groups differed markedly in the brain response to emotional distractors; younger adults activated posterior cortical regions and the striatum, and older adults activated frontal regions. Also, an age by valence interaction was found for IFG and ACC, suggesting differential modulation of attention to task-relevant emotional information. These results provide new insights into age-related changes in emotional processing and the ability to resolve interference from emotional distraction.