Longitudinal Changes in Intellectual Development in Children with Fragile X Syndrome

Structural equation modeling (SEM) was used to examine the development of intellectual functioning in 145 school-age pairs of siblings. Each pair included one child with Fragile X syndrome (FXS) and one unaffected sibling. All pairs of children were evaluated on the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) at time 1 and 80 pairs of children received a second evaluation at time 2 approximately 4 years later. Compared to their unaffected siblings, children with FXS obtained significantly lower percentage correct scores on all subtests of the WISC at both time points. During the time between the first and second assessments, the annual rate of intellectual development was approximately 2.2 times faster in the unaffected children compared to the children with FXS. Levels of the fragile X mental retardation protein (FMRP) were highly associated with intellectual ability scores of the children with FXS at both time points (r=0.55 and 0.64 respectively). However, when gender, age, and the time between assessments were included as covariates in the structural equation model, FMRP accounted for only 5% of the variance in intellectual ability scores at time 1 and 13% of the variance at time 2. The results of this study suggest that slower learning contributes to the low and declining standardized IQ scores observed in children with FXS.     

A longitudinal panel study on antecedents and outcomes of work-home interference

Theoretical models of the antecedents and outcomes of work-home interference (WHI) suggest that work characteristics (e.g., job stressors, working hours) increase the probability that an individual experiences work-home interference. Since work-home interference is considered as a role stressor, these experiences should be detrimental for long-term well-being. In this 2-wave panel study, the authors compared this suggested pathway with competing models that propose reverse causation and reciprocal effects in a sample of 365 employees (N at T2 = 130) from the German workforce using structural equation modeling. In particular, a model with two proposed antecedents (job stressors, working hours) of WHI and two proposed consequences (depression, turnover motivation) was analyzed in alternative configurations. The results support a cyclical model with a job stressors → depression → WHI → job stressors pathway. Furthermore, working hours affected WHI, and turnover motivation emerged as an outcome of WHI.     

Children's sensitivity to circular explanations

The ability to evaluate the quality of explanations is an essential part of children's intellectual growth. Explanations can be faulty in structural ways such as when they are circular. A circular explanation reiterates the question as if it were an explanation rather than providing any new information. Two experiments (N=77) examined children's preferences when faced with circular and noncircular explanations. The results demonstrate that a preference for noncircular explanations is present, albeit in a fragile form, by 5 or 6 years of age and that it appears robustly by 10 years of age. Thus, the ability to evaluate the quality of explanations based on structural grounds appears to develop rapidly during the elementary school years.     

Behavioral and ERP measures of holistic face processing in a composite task

Holistic processing of faces is characterized by encoding of the face as a single stimulus. This study employed a composite face task to examine whether holistic processing varies when attention is restricted to the top as compared to the bottom half of the face, and whether evidence of holistic processing would be observed in event-related potentials. Analyses of behavioral data showed that spatial misalignment of the face halves disrupted holistic processing and enhanced detection of repeated attended halves. Effects of misalignment on the N170, VPP and N250 ERP components resembled effects of face inversion. Attention to the top half of the face was associated with faster P1, N170, VPP, and P2 latencies than attending to the bottom, suggesting automatic processing of the eye region. Further, N170 latency effects suggested that structural encoding of the face is facilitated during holistic processing. N250 latency effects reflected task difficulty. Finally, an overall right hemispheric asymmetry was most pronounced when holistic face processing was greatest. Results are discussed in light of recent proposals that holistic face processing is a subtype of configural face processing.     

Factor Indeterminacy as Metrological Uncertainty: Implications for Advancing Psychological Measurement

Researchers have long been aware of the mathematics of factor indeterminacy. Yet, while occasionally discussed, the phenomenon is mostly ignored. In metrology, the measurement discipline of the physical sciences, uncertainty – distinct from both random error (but encompassing it) and systematic error – is a crucial characteristic of any measurement. This research argues that factor indeterminacy is uncertainty. Factor indeterminacy fundamentally threatens the validity of psychometric measurement, because it blurs the linkage between a common factor and the conceptual variable that the factor represents. Acknowledging and quantifying factor indeterminacy is important for progress in reducing this component of uncertainty in measurement, and thus improving psychological measurement over time. Based on our elaborations, we offer a range of recommendations toward achieving this goal.     

Shared structure need not be shared set-structure

Recent semantic approaches to scientific structuralism, aiming to make precise the concept of shared structure between models, formally frame a model as a type of set-structure. This framework is then used to provide a semantic account of (a) the structure of a scientific theory, (b) the applicability of a mathematical theory to a physical theory, and (c) the structural realist’s appeal to the structural continuity between successive physical theories. In this paper, I challenge the idea that, to be so used, the concept of a model and so the concept of shared structure between models must be formally framed within a single unified framework, set-theoretic or other. I first investigate the Bourbaki-inspired assumption that structures are types of set-structured systems and next consider the extent to which this problematic assumption underpins both Suppes’ and recent semantic views of the structure of a scientific theory. I then use this investigation to show that, when it comes to using the concept of shared structure, there is no need to agree with French that “without a formal framework for explicating this concept of ‘structure-similarity’ it remains vague, just as Giere’s concept of similarity between models does ...” (French, 2000, Synthese, 125, pp. 103–120, p. 114). Neither concept is vague; either can be made precise by appealing to the concept of a morphism, but it is the context (and not any set-theoretic type) that determines the appropriate kind of morphism. I make use of French’s (1999, From physics to philosophy (pp. 187–207). Cambridge: Cambridge University Press) own example from the development of quantum theory to show that, for both Weyl and Wigner’s programmes, it was the context of considering the ‘relevant symmetries’ that determined that the appropriate kind of morphism was the one that preserved the shared Lie-group structure of both the theoretical and phenomenological models. I wish to thank Katherine Brading, Anjan Chakravartty, Steven French, Martin Thomson-Jones, Antigone Nounou, Stathis Psillos, Dean Rickles, Mauricio Suarez and two anonymous referees for valuable comments and criticisms, and Gregory Janzen for editorial suggestions. Research for this paper was funded by a generous SSHRC grant for which I am grateful     

The Multidimensional Nature of Social Cohesion: Psychological Sense of Community, Attraction, and Neighboring

Items from the Neighborhood Cohesion Instrument were completed by 1,732 individuals from a random sample of households in 20 rural communities across Canada during the summer of 2001. Confirmatory factor analysis of the NCI items based on polychoric correlations and weighted least squares estimation found three underlying latent variables. Although items were related to the three latent variables in a somewhat different manner than they were in Buckner's original study, the same three latent variables were evident, providing convincing evidence that social cohesion has at least three subscales: psychological sense of community, neighboring, and attraction. Correlations between subscales were relatively high (between .67 and .87). Intraclass correlation coefficients for the three scales were .115, .127, and .112. In addition, the community means differed on different subscales in a manner that related to recognized characteristics of the communities. Thus the subscales are appropriate measures for both individuals and communities and can be recommended for further research on social cohesion.     

For-profit/nonprofit differences in center-based child care quality: Results from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development

In secondary analyses of National Institute of Child Health and Human Development Study of Early Child Care and Youth Development data, multiple indicators of quality (caregiver wages and turnover; child/staff ratio; caregiver education and professionalism; positive caregiving) were compared between child care centers by sector (for-profit/nonprofit) and subsector (for-profit independent/chain, nonprofit church/nonchurch) at multiple points from infancy through prekindergarten. Nonprofit centers evidenced higher caregiver wages and education at most ages and better quality child/staff ratios, turnover, caregiver professionalism, and positive caregiving for toddlers and preschoolers. Subsector differences in preschool classrooms were more complex. In general, quality was higher in nonprofit non-religiously affiliated centers, intermediate in nonprofit religiously affiliated and for-profit independent centers, and lower in for-profit chains, but differences were not found on every indicator or between every group. Further, for-profit chain status predicted lower quality positive caregiving, controlling for family characteristics, staff, and structural quality, at 54 months, but not 36 months. Results support and extend prior research by controlling for family characteristics. Policy implications regarding supply- and demand-side quality-improvement strategies that address market competition and parent choice across subsectors are discussed.     

Faulty assumptions: A comment on Blanton, Jaccard, Gonzales, and Christie (2006)

Blanton, Jaccard, Gonzales, and Christie [Blanton, H., Jaccard, J., Gonzales, P., Christie, C. (2006). Decoding the Implicit Association Test: implications for criterion prediction. Journal of Experimental Social Psychology, 42, 192-212.] assert that the Implicit Association Test (IAT) imposes a model that portrays relative preferences as the additive difference between single attitudes. This assertion is misplaced because relative preferences do not necessarily reduce to component attitudes. BJGC also assume that the IAT conditions represent two indicators of the same construct. This assumption is incorrect, and is the cause of their poor-fitting models. The IAT, like other experimental paradigms, contrasts performance between interdependent conditions, and cannot be reduced to component parts. This is true whether calculating a simple difference between conditions, or using the IAT D score. D—an individual effect size that is monotonically related to Cohen’s d—codifies the interdependency between IAT conditions. When their unjustified psychometric assumptions are replaced with plausible assumptions, the models fit their data very well, and basis for their poor-fitting models becomes clear.     

Eating disorder pathology among overweight treatment-seeking youth: clinical correlates and cross-sectional risk modeling

Preliminary research suggests that pediatric overweight is associated with increased eating disorder pathology, however, little is known about which overweight youth are most vulnerable to eating disorder pathology. We therefore investigated 122 overweight treatment-seeking youth to describe eating disorder pathology and mental health correlates, and to identify psychopathological constructs that may place overweight youth at increased risk for eating disorder pathology. Youth participated in a comprehensive assessment of eating disorders, mood and anxiety disorders, general psychopathology, and risk variables involving semi-structured clinical interviews and self- and parent-report questionnaires prior to the initiation of weight-loss treatment. Ten youth met criteria for an eating disorder, and over one-third endorsed recent binge eating. Eating disorder pathology was associated with depressive and anxious symptoms (p's<0.001). Structural equation modeling indicated increased negative affect, teasing experience, and thin-ideal internalization, and decreased perfectionism were associated with increased eating disorder pathology. Findings corroborate earlier work indicating that eating disorder pathology is elevated and clinically significant in overweight treatment-seeking youth, bolstering the need for mental health assessment of such individuals. Cross-sectional modeling proposed key variables that relate to eating disorder pathology in overweight treatment-seeking youth, which following prospective replication, may inform the development of effective interventions for overweight and eating disorders.