Single‐item big five ratings in a social network design

To develop and validate an ultra‐short measure to assess the Big Five in social network designs, the unipolar items of the Ten‐Item Personality Inventory were adapted to create a bipolar single‐item scale (TIPI‐r), including a new Openness item. Reliability was examined in terms of the internal consistency and test–retest stability of self‐ratings and peer‐rating composites (trait reputations). Validity was examined by means of convergence between TIPI‐r and Big Five Inventory (BFI) scores, self‐peer agreement and projection (intra‐ individual correlation between self‐ and peer‐ratings). The psychometric quality of the TIPI‐r differed somewhat between scales and the different reliability and validity criteria. The high reliability of the peer‐rating composites motivates to use the TIPI‐r in future studies employing social network designs. Copyright © 2007 John Wiley & Sons, Ltd.     

The Development of Delinquency and Perceived Friendship Quality in Adolescent Best Friendship Dyads

The present study examines both the unique and the combined role of best friends' delinquency and perceived friendship quality in the development of adolescent delinquency. Questionnaire data were gathered from 435 Dutch adolescent best friends (mean age at first wave = 12.97) over a period of 5 years with annual assessments. Results showed that mean levels of delinquency and perceived friendship quality increased over time. Adolescent best friends were highly similar in both mean levels and changes in delinquency over time. For boys, similarity in mean level delinquency between best friends was higher than for girls. In addition, only for boys, friends' delinquency is associated with increases in adolescent delinquency over time, and adolescents' delinquency is associated with increases in friends' delinquency over time. No bidirectional longitudinal associations were found between perceived friendship quality and adolescent delinquency. No interaction effects between friendship quality and friends' delinquency on adolescent delinquency were found. Thus, findings were more in support of the differential association theory than of the social control theory.     

Emerging Late Adolescent Friendship Networks and Big Five Personality Traits: A Social Network Approach

ABSTRACT The current study focuses on the emergence of friendship networks among just‐acquainted individuals, investigating the effects of Big Five personality traits on friendship selection processes. Sociometric nominations and self‐ratings on personality traits were gathered from 205 late adolescents (mean age=19 years) at 5 time points during the first year of university. SIENA, a novel multilevel statistical procedure for social network analysis, was used to examine effects of Big Five traits on friendship selection. Results indicated that friendship networks between just‐acquainted individuals became increasingly more cohesive within the first 3 months and then stabilized. Whereas individuals high on Extraversion tended to select more friends than those low on this trait, individuals high on Agreeableness tended to be selected more as friends. In addition, individuals tended to select friends with similar levels of Agreeableness, Extraversion, and Openness.     

Bayesian model selection of informative hypotheses for repeated measurements

When analyzing repeated measurements data, researchers often have expectations about the relations between the measurement means. The expectations can often be formalized using equality and inequality constraints between (i) the measurement means over time, (ii) the measurement means between groups, (iii) the means adjusted for time-invariant covariates, and (iv) the means adjusted for time-varying covariates. The result is a set of informative hypotheses. In this paper, the Bayes factor is used to determine which hypothesis receives most support from the data. A pivotal element in the Bayesian framework is the specification of the prior. To avoid subjective prior specification, training data in combination with restrictions on the measurement means are used to obtain so-called constrained posterior priors. A simulation study and an empirical example from developmental psychology show that this prior results in Bayes factors with desirable properties.     

Developmental Trajectories of Perceived Friendship Intimacy,Constructive Problem Solving,and Depression from Early to Late Adolescence

This study examined friendship types in developmental trajectories of perceived closeness and balanced relatedness. In addition, differences between friendship types in the development of constructive problem solving and depression were examined. Questionnaire data of five annual waves were used from two adolescent cohorts (cohort 1: M = 12.41 years; cohort 2: M = 16.37 years). Growth Mixture Modeling revealed two developmental trajectories in cognitive representations of perceived friendship intimacy: interdependent and disengaged friendships. Adolescents in interdependent friendships were characterized by high perceived closeness and balanced relatedness across adolescence. Furthermore, adolescents in disengaged friendships had lower levels of and smaller increases in constructive problem solving. Girls in disengaged friendships showed smaller increases in balanced relatedness and higher levels of depression than boys in disengaged friendships and adolescents in interdependent friendships.