Birds of a feather sit together: physical similarity predicts seating choice

Across four studies, people sat (or reported they would sit) closer to physically similar others. Study 1 revealed significant aggregation in seating patterns on two easily observed characteristics: glasses wearing and sex. Study 2 replicated this finding with a wider variety of physical traits: race, sex, glasses wearing, hair length, and hair color. The overall tendency for people to sit beside physically similar others remained significant when controlling for sex and race, suggesting people aggregate on physical dimensions other than broad social categories. Study 3 conceptually replicated these results in a laboratory setting. The more physically similar participants were to a confederate, the closer they sat before an anticipated interaction when controlling for sex, race, and attractiveness similarity. In Study 4, overall physical similarity and glasses wearing similarity predicted self-reported seating distance. These effects were mediated by perceived attitudinal similarity. Liking and inferred acceptance also received support as mediators for glasses wearing similarity.     

Predicting recidivism with the Psychopathy Checklist: are factor score composites really necessary?

In two previous studies on general and violent recidivism (Walters & Heilbrun, 2010; Walters, Knight, Grann, & Dahle, 2008), the summed composite antisocial facet of the Psychopathy Checklist displayed incremental validity relative to the other 3 facets (interpersonal, affective, lifestyle), whereas the other 3 facets generally failed to demonstrate incremental validity relative to the antisocial facet. Because summed composite scores do not account for ordinal item distributions, the 6 Walters et al. (2008) samples were reanalyzed with factor score composites derived from a 4-factor confirmatory factor analysis. The results, however, showed little change from what had been obtained earlier with summed composite scores. Two additional samples not previously included in any incremental validity analyses of the Psychopathy Checklist evidenced a 3-factor structure, with the lifestyle and antisocial facets merged into a single factor. This single factor displayed incremental validity relative to the interpersonal and affective facets, but the reverse was not true regardless of whether summed composite scores or factor score composites were used. A comparison of zero-order correlations from all 8 samples revealed that the antisocial summed composite score predicted significantly better than the summed composite scores for the other 3 facets and that a superordinate factor failed to improve on the performance of either the antisocial summed composite score or the antisocial factor score composite.     

Dilution, not load, affects distractor processing

Lavie and Tsal (1994) proposed that spare attentional capacity is allocated involuntarily to the processing of irrelevant stimuli, thereby enabling interference. Under this view, when task demands increase, spare capacity should decrease and distractor interference should decrease. In support, Lavie and Cox (1997) found that increasing perceptual load by increasing search set size decreased interference from an irrelevant distractor. In three experiments, we manipulated the cue set size (number of cued locations) independently of the display set size (number of letters presented). Increasing the display set size reduced distractor interference regardless of whether the additional letters were relevant to the task. In contrast, increasing the cue set size increased distractor interference. Both findings are inconsistent with the load explanation, but are consistent with a proposed two-stage dilution account.     

Observation and physical practice: coding of simple motor sequences

An experiment was conducted to determine the coordinate system used in the development of movement codes during observation and utilized on later physical practice performance of a simple spatial-temporal movement sequence. The task was to reproduce a 1.3-s spatial-temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention test and two transfer tests was used: a mirror transfer test where the same pattern of muscle activation and limb joint angles was required and a nonmirror transfer test where the visual-spatial pattern of the sequence was reinstated on the transfer test. The results indicated a strong advantage for participants in the physical practice condition when transferred to the mirror condition in which the motor coordinates (e.g., pattern of muscle activation and joint angles) were reinstated relative to transfer performance when the visual-spatial coordinates were reinstated (visual and spatial location of the target waveform). The observation group, however, demonstrated an advantage when the visual-spatial coordinates were reinstated. These results demonstrate that codes based in motor coordinates can be developed relatively quickly for simple rapid movement sequences when participants are provided physical practice, but observational practice limits the system to the development of codes based in visual-spatial coordinates. Performances of control participants, who were not permitted to practise or observe the task, were quite poor on all tests.     

The functions of nonsuicidal self-injury: support for cognitive-affective regulation and opponent processes from a novel psychophysiological paradigm

Although research on the reasons for engaging in nonsuicidal self-injury (NSSI) has increased dramatically in the last few years, there are still many aspects of this pernicious behavior that are not well understood. The purpose of this study was to address these gaps in the literature, with a particular focus on investigating whether NSSI (a) regulates affective valence in addition to affective arousal and (b) serves a cognitive regulation function in addition to an affect regulation function. To elucidate these issues, the present study utilized a sample of 112 participants (33 controls, 39 no pain controls, 16 NSSI individuals, and 24 controls matching the affect dysregulation levels of the NSSI group), employed psychophysiological measures of affective valence (startle-alone reactivity) and quality of information processing (prepulse inhibition), and used experimental methods involving an NSSI-proxy to model the NSSI process. Results largely were consistent with predictions, supporting the hypotheses that NSSI serves to regulate cognitive processing and affective valence. On this latter point, however, the control groups also showed a decrease in negative affective valence after the NSSI-proxy. This unexpected finding is consistent with the hypothesis that opponent processes may contribute to the development of self-injurious behaviors (Joiner, 2005). Overall, the present study represents an important extension of previous laboratory NSSI studies and provides a fertile foundation for future studies aimed at understanding why people engage in NSSI.     

Beyond Thinness: The Influence of a Curvaceous Body Ideal on Body Dissatisfaction in Black and White Women

This study examined whether a curvaceous body ideal differentially influenced sources of body dissatisfaction in 116 Black and 222 White women at a northeastern U.S. university. We measured idealization of and dissatisfaction with three components of a curvaceous ideal: breast size, buttock size, and weight. Although most women preferred a curvaceous body shape, more White women preferred this ideal to be slender with medium breasts whereas more Black women preferred this ideal to be curvier with medium breasts and large buttocks. Women discrepant from these ideals reported more dissatisfaction. Dissatisfaction with the curvaceous ideal predicted appearance concerns. Findings highlight the need to consider valued body ideals other than thinness as potential sources of dissatisfaction among women of different racial/ethnic backgrounds.     

A cross-sequential analysis of developmental differences in speed of visual information processing

Development of processing speed was examined in three backward masking studies. The first verified the central nature of backward masking for children aged 8 and 11 years and for adults. The second suggested that task requirements were equivalent for children similar to those in Study 1, and that age differences in performance were not attributable to nonprocessing variables. The main cross-sequential study estimated speed of processing in 80 children (approximately 6 years to 13 years) and young adults using an inspection time task. Target exposure duration was varied to establish the time required to achieve a high level of discriminative accuracy. Estimates of processing speed increased until about 11-13 years of age; beyond this, the trend was less obvious, and it is possible that inspection time asymptotes at around the onset of adolescence. Performance improvement after 1 year could not be explained as resulting from practice since improvement among controls over a period of 2 weeks was significantly less. Correlations between estimates of inspection time made up to 2 years apart found the measure to be reliable.     

Seeking a Balance Between the Statistical and Scientific Elements in Psychometrics

In this paper, I will review some aspects of psychometric projects that I have been involved in, emphasizing the nature of the work of the psychometricians involved, especially the balance between the statistical and scientific elements of that work. The intent is to seek to understand where psychometrics, as a discipline, has been and where it might be headed, in part at least, by considering one particular journey (my own). In contemplating this, I also look to psychometrics journals to see how psychometricians represent themselves to themselves, and in a complementary way, look to substantive journals to see how psychometrics is represented there (or perhaps, not represented, as the case may be). I present a series of questions in order to consider the issue of what are the appropriate foci of the psychometric discipline. As an example, I present one recent project at the end, where the roles of the psychometricians and the substantive researchers have had to become intertwined in order to make satisfactory progress. In the conclusion I discuss the consequences of such a view for the future of psychometrics.     

Age-related changes in motor imagery from early childhood to adulthood: Probing the internal representation of speed-accuracy trade-offs

The purpose of this study was to chart the development of motor imagery ability between 5 and 29 years of age and its relationship to fine-motor skill. 237 participants performed a computerized Virtual Radial Fitts Task (VRFT) as a measure of Motor Imagery (MI) ability. Participants aimed at five targets, positioned along radial axes from a central target circle. The targets differed in width over trials (2.5, 5, 10, 20 or 40 mm). Performance was indexed by the relationship between the movement time (MT) in executed and imagined movements. A subset of participants (11–19 years old, n = 22) also performed the task with their non-preferred hand. We also examined if manual skill (measured by peg board task and posting coins) was related to the executed and imagined MT on the VRFT. Our results showed that the accuracy of the imagined movement improved steadily over childhood, reaching an asymptote during adolescence and into early adulthood. The correlation between the real and virtual MT using the preferred hand did not differ appreciably from that using the non-preferred hand. If the children could perform the tasks with their non-preferred hand (11 years and older), they also scaled performance in relatively precise terms using the less dextrous non-preferred hand. The correlation between real MT on the VRFT and fine-motor performance ranged between .53 and .42, while that for virtual movement was between .37 and .34. MI ability predicts manual skill to a moderate degree.