The Pen Is Not Always Mightier: Different Ways of Measuring Handedness With the Edinburgh Handedness Inventory Yield Different Handedness Conclusions.

Although consistency of handedness (the strength of dominant hand preference) is increasingly recognized as an important individual difference, there are questions about how to best measure it. A recent meta-analysis showed that researchers have often failed to report details of responses and response formats to handedness test items. In addition to measuring handedness direction (i.e., left versus right handedness), there can be utility to dichotomizing the Edinburgh Handedness Inventory (EHI) into consistent and inconsistent dominant handedness, despite controversy over the best means of doing so. In this study, we performed a discriminant function analysis of EHI items to determine which items best predicted handedness consistency versus handedness direction. Although the same discriminant function accounted for most of the variance for both dependent measures, writing and drawing EHI items were the strongest predictors of handedness direction and combing and opening jars items were the strongest predictors of handedness consistency. As different items on the EHI predicted these different handedness dimensions, we discuss the implications of dichotomizing EHI items into both relevant dimensions for both biological and environmental theories of the basis of handedness and for future handedness research.

Predictors of sibling victimization and associations with self-perception and relationship attachment in adolescence.

Research has shown that sibling victimization may be as detrimental to adolescent outcomes as peer victimization. However, many questions remain unanswered with regard to potential protective parenting factors and consequences sibling victimization among adolescents. This study tested a mediation model of sibling victimization with parental monitoring, a positive parenting factor, as a predictor and parent and peer-adolescent attachment as mediated by adolescent self-perceptions as potential outcomes. A three path mediation from parental monitoring → sibling victimization → adolescent self-perceptions → peer/parent-adolescent attachment was also tested. Structural Equation Modeling revealed that parental monitoring was negatively associated with sibling victimization only for girls. Sibling victimization had negative direct and indirect effects on parent- and peer-adolescent attachment via adolescent self-perceptions of social competence and self-worth. Findings suggest that parental monitoring may be important in the prevention of sibling victimization and self-perceptions may be an important point of intervention adolescents experiencing sibling victimization.