Fractional designs: A simulation study of usefulness in the social sciences

Fractional designs can be extremely useful in social science research, especially when a large number of factors is involved. Reluctance for the use of fractional designs seems to be warranted for two reasons: (1) In the social sciences, the amount of measurement error is often large, which may decrease the power, and (2) higher order interactions are assumed to be nonsignificant, which is difficult to guarantee without sufficient research. This simulation study shows the effects of measurement error and assumption violations under various conditions. It is concluded that fractional designs handle measurement error gracefully and that they are as powerful as a full design when equal degrees of freedom are available. Significant interaction effects can cause serious problems, especially in situations with low or intermediate measurement error, and can lead to erroneous conclusions. Only when estimated confounded effects are clearly not significant, the chance of a wrong decision is reasonably small. Therefore, fractional designs are especially warranted for the exclusion of irrelevant factors. However, we note pitfalls in the use of Version 1.0 of the program Trail Run from SPSS, Inc., to implement the procedures.     

Dispositional Anxiety and Frontal‐Midline Theta: On the Modulatory Influence of Sex and Situational Threat

In their adaptive control hypothesis, Cavanagh and Shackman (2015) recently claimed that dispositional anxiety is correlated with frontal‐midline theta (FMθ) as a generic “need for control” signal of the anterior midcingulate cortex. Here, we tested this assumption, also considering potential modulatory influences of anticipatory threat and individuals’ sex. In a nonclinical sample of 168 participants (84 women), electroencephalogram was recorded while individuals performed a simple two‐choice task. Half of the participants were assigned to a threat anticipation condition (anticipation of public speaking), whereas the other half was assigned to a control condition. State anxiety was monitored across the experiment. Dispositional anxiety was assessed by self‐report scales, which were completed before individuals came to the laboratory. Target stimuli in the two‐choice task induced a transient increase in FMθ power that was subject to an interaction of dispositional anxiety, sex, and experimental group. Only in women who anticipated public speaking did we observe a substantial positive relation between dispositional anxiety and general FMθ power. Our results indicate that the link between dispositional anxiety and FMθ is not universal but rather depends on complex interactions of individuals’ sex and situational threat.     

The cycle of violence as a function of PTSD and appetitive aggression: A longitudinal study with Burundian soldiers

During deployment, soldiers face situations in which they are not only exposed to violence but also have to perpetrate it themselves. This study investigates the role of soldiers' levels of posttraumatic stress disorder (PTSD) symptoms and appetitive aggression, that is, a lust for violence, for their engaging in violence during deployment. Furthermore, factors during deployment influencing the level of PTSD symptoms and appetitive aggression after deployment were examined for a better comprehension of the maintenance of violence. Semi-structured interviews were conducted with 468 Burundian soldiers before and after a 1-year deployment to Somalia. To predict violent acts during deployment (perideployment) as well as appetitive aggression and PTSD symptom severity after deployment (postdeployment), structural equation modeling was utilized. Results showed that the number of violent acts perideployment was predicted by the level of appetitive aggression and by the severity of PTSD hyperarousal symptoms predeployment. In addition to its association with the predeployment level, appetitive aggression postdeployment was predicted by violent acts and trauma exposure perideployment as well as positively associated with unit support. PTSD symptom severity postdeployment was predicted by the severity of PTSD avoidance symptoms predeployment and trauma exposure perideployment, and negatively associated with unit support. This prospective study reveals the importance of appetitive aggression and PTSD hyperarousal symptoms for the engagement in violent acts during deployment, while simultaneously demonstrating how these phenomena may develop in mutually reinforcing cycles in a war setting.     

A semiparametric approach for item response function estimation to detect item misfit

When scaling data using item response theory, valid statements based on the measurement model are only permissible if the model fits the data. Most item fit statistics used to assess the fit between observed item responses and the item responses predicted by the measurement model show significant weaknesses, such as the dependence of fit statistics on sample size and number of items. In order to assess the size of misfit and to thus use the fit statistic as an effect size, dependencies on properties of the data set are undesirable. The present study describes a new approach and empirically tests it for consistency. We developed an estimator of the distance between the predicted item response functions (IRFs) and the true IRFs by semiparametric adaptation of IRFs. For the semiparametric adaptation, the approach of extended basis functions due to Ramsay and Silverman (2005) is used. The IRF is defined as the sum of a linear term and a more flexible term constructed via basis function expansions. The group lasso method is applied as a regularization of the flexible term, and determines whether all parameters of the basis functions are fixed at zero or freely estimated. Thus, the method serves as a selection criterion for items that should be adjusted semiparametrically. The distance between the predicted and semiparametrically adjusted IRF of misfitting items can then be determined by describing the fitting items by the parametric form of the IRF and the misfitting items by the semiparametric approach. In a simulation study, we demonstrated that the proposed method delivers satisfactory results in large samples (i.e., N ≥ 1,000).     

Warm or competent? Improving intergroup relations by addressing threatened identities of advantaged and disadvantaged groups

Applying the Needs‐Based Model of Reconciliation to contexts of group disparity, two studies examined how messages from outgroup representatives that affirmed the warmth or competence of advantaged or disadvantaged groups influenced their members' intergroup attitudes. Study 1 involved natural groups differing in status; Study 2 experimentally manipulated status. In both studies, advantaged‐group members responded more favorably, reporting more positive outgroup attitudes and willingness to change the status quo toward equality, to messages reassuring their group's warmth. Disadvantaged‐group members responded more favorably to messages affirming their group's competence. Study 2 further demonstrated that the effectiveness of reassuring a disadvantaged group's competence stemmed from restoring its threatened dimension of identity, irrespective of a change of the status quo. In line with Social Identity Theory (Tajfel & Turner, 1979), these results indicate that beyond the competition over tangible resources, groups are concerned with restoring threatened dimensions of their identities. Exchanging messages that remove identity‐related threats may promote not only positive intergroup attitudes but also greater willingness to act collectively for intergroup equality. Copyright © 2013 John Wiley & Sons, Ltd.     

Effectiveness of online word of mouth on exposure to an Internet-delivered intervention

The use of online word of mouth (WOM) seems a promising strategy to motivate young people to visit Internet-delivered interventions. An Internet-delivered intervention aimed at changing implicit attitudes related to alcohol was used in two experiments to test effectiveness of e-mail invitations on a first visit to the intervention. The results of the first experiment (N = 196) showed that an invitation by e-mail from a friend was more effective to attract young adults (aged 18–24 years) to the intervention website than an invitation from an institution. A 2 × 2 design was used in the second experiment (N = 236) to test manipulations of argument strength and the use of peripheral cues in invitations. Results showed that weak arguments were more effective to attract young adults to the intervention website when an incentive was withheld. These results need to be taken into account when using online WOM as a strategy to improve exposure to Internet-delivered interventions.     

Positive Self‐regard and Claim to Leadership: Two Fundamental Forms of Self‐evaluation

The present article examines the common factor structure of various self‐evaluative personality constructs. Consistent with previous research, we found considerable redundancy between constructs. Two basic forms of self‐evaluation could be distinguished: Positive Self‐regard (PSR) reflects people's contentedness with themselves in comparison with their own standards. Constructs such as depression, self‐esteem and neuroticism have very high loadings on this factor. In contrast, Claim to Leadership (CTL) reflects the subjective conviction that one is called to take charge and lead others. This conviction is often called ‘narcissism’. PSR mainly reflects an intra‐personal kind of self‐evaluation, whereas CTL reflects an inter‐personal kind. Both forms of self‐evaluation independently predict intellectual self‐enhancement, but only one of them (PSR) also predicts self‐reported mental health. Moreover, the two forms of self‐evaluation are differentially associated with self‐reported and peer‐reported inter‐personal traits (Dominance and Affiliation). Finally, the concepts of ‘Grandiosity’ and ‘Vulnerability’ from narcissism research may easily be reframed in terms of CTL and PSR. The two‐dimensional framework may help overcome the conceptual confusion that exists around different forms of self‐evaluation and streamline the field for future research. Copyright © 2013 European Association of Personality Psychology     

Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind

Theory of Mind (ToM) is the ability to infer other people’s mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM.