Examining measures of schizotypy for gender and racial bias using item response theory and differential item functioning.

Schizotypy involves schizophrenia-like traits and symptoms, with the Wisconsin Schizotypy Scales (WSS) being frequently used in previous research. There is some evidence that schizophrenia-spectrum symptom levels, including when using the WSS, might vary both by gender and by race and ethnicity. However, previous research has rarely examined to what extent the WSS show gender and racial bias. Further, this has not been previously examined for the Cognitive Slippage Scale, a measure of disorganized schizotypy. In this study, we examined biases for a subset of items from the WSS in a large sample of undergraduate students (n = 21,829). Using item response theory to test for levels of differential item functioning (DIF), we found some evidence of problematic DIF for all scales, including for negative, positive, and disorganized schizotypy scales. There was evidence of problematic DIF especially by gender and for Black and Multiracial participants. Overall, the current results suggest that gender and/or racial bias on these scales should be an important consideration in using these scales and our results could have implications for assessment of schizophrenia-spectrum symptoms.

Differential item functioning of the Multidimensional Schizotypy Scale and Multidimensional Scale-Brief across ethnicity.

Schizotypy refers to traits or symptoms similar to schizophrenia, but in a diminished form, and schizotypy is thought to reflect a liability for the future development of schizophrenia. The Multidimensional Schizotypy Scale (MSS) is a new measure of schizotypy that improves on existing measures. The MSS contains full and brief subscales for positive, negative, and disorganized schizotypy. Although MSS scores have been validated in a variety of populations, the scales have not been thoroughly examined for differential item functioning in East Asian, Southeast Asian, Hispanic, Multiracial, and White participants. The current study included 567 East Asian, 351 Southeast Asian, 360 Hispanic, 230 Multiracial, and 345 White undergraduate participants from the United States. Overall, few of the items in the full or brief versions of the scales displayed differential item functioning across groups. The full and brief versions of the scales also displayed similar and not-significantly different validity coefficients with the Detachment and Psychoticism scales of the Personality Inventory for DSM-5. These findings suggest that the MSS measures the same constructs across ethnic groups, and the scale scores represent the same latent level of schizotypy among groups. Future research may use the MSS in these diverse groups without concern that the psychometric properties differ significantly among groups. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A reassessment of the higher-order factor structure of the German Schizotypal Personality Questionnaire (SPQ-G) in German-speaking adults.

The Schizotypal Personality Questionnaire (SPQ) is a widely-used self-report instrument for the assessment of schizotypal personality traits. However, the factor structure of scores on English and non-English translations of the SPQ has been a matter of debate. With little previous factorial evaluation of the German version of the SPQ (SPQ-G), we re-assessed the higher-order factor structure of the measure. A total of 2,428 German-speaking adults from Central Europe (CE) and the United Kingdom (UK) completed the SPQ-G. Confirmatory factor analysis - testing proposed 2-, 3-, and 4-factor models of SPQ-G scores - indicated that the 4-factor solution had best fit. Partial measurement invariance across cultural group (CE and UK) and sex was obtained for the 4-factor model. Further analyses showed CE participants had significantly higher scores than UK participants on one schizotypal facet. These results suggest that scores on the SPQ-G are best explained in terms of a higher-order, 4-factor solution in German migrant and non-migrant adults.

The Network Structure of Schizotypal Personality Traits.

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.

Psychometric properties of the Malay Schizotypal Personality Questionnaire: Measurement invariance and latent mean comparisons in Malaysian adults.

INTRODUCTION: The Schizotypal Personality Questionnaire (SPQ) is a widely used self-report measurement instrument for the assessment of schizotypal personality traits. However, the factor structure of the SPQ has been a matter of some debate. As a contribution to this debate, we examined the factor structure of the SPQ in Malaysian adults. METHOD: A total of 382 Malaysian adults completed a Malay translation of the SPQ. Confirmatory factory analysis was used to examine the fit of 3- and 4-factor solutions for the higher-order dimensionality of the SPQ. Ethnic invariance for the best-fitting model was tested at the configural, metric, and scalar levels, and a multivariate analysis of variance was used to examine sex and ethnicity differences in domain scores. RESULTS: The 4-factor model provided a better fit to the data than did the 3-factor model. The 4-factor model also demonstrated partial measurement invariance across ethnic groups. Latent mean comparisons for sex and ethnicity revealed a number of significant differences for both factors, but effect sizes were small. DISCUSSION: The 4-factor structure of the SPQ received confirmatory support and can be used in Malay-speaking populations.

Measurement invariance of the Schizotypal Personality Questionnaire in Asian, Pacific Islander, White, and multiethnic populations.

The Schizotypal Personality Questionnaire (SPQ; Raine, 1991) is one of the most commonly used self-report measures of schizotypal personality traits. Previous work has found that the SPQ has a 3- or 4-factor structure, but most of this work was with White participants. Little is known about the psychometric properties of the scale in Pacific Islander populations, and some evidence suggests scores may differ between White and Asian participants. The current study included 398 Asian, 293 White, 159 Pacific Islander, and 308 multiethnic nonclinical participants. A 4-factor model fit the data well, and this factor structure displayed configural and metric invariance, suggesting that the factor structure is the same across these diverse groups. However, results provided mixed evidence for scalar invariance, suggesting the scale may lack scalar invariance in these populations. Follow-up analyses revealed that the questionable scalar invariance was related to the intercepts of the Ideas of Reference and Suspiciousness subscales in the White sample. This suggests that mean comparisons among ethnic groups involving the Ideas of Reference and Suspiciousness subscales are not appropriate.

Cross-cultural invariance of the factor structure of the Schizotypal Personality Questionnaire across Spanish and American college students.

The main goal of this study was to examine the cross-cultural invariance of the factor structure of the Schizotypal Personality Questionnaire (SPQ) (Raine, 1991) in two large samples of Spanish and American young adults. The final sample was made up of 2313 college students (508 men, 22%). Their mean age was 20.5 years (S.D.=3.2). The results indicated that the Stefanis et al. (2004) four-factor model yielded the best goodness-of-fit indices compared to alternative models. Moreover, the results support configural, metric, and partial measurement invariance of the covariances of the SPQ across the two samples. The finding of measurement equivalence across cultures provides essential evidence of construct validity for the schizotypy dimensions and of the cross-cultural validity of SPQ scores. The finding of comparable dimensional structures in cross-cultural samples lends further support to the continuum model of schizotypy and schizophrenia spectrum disorders. Future studies should continue to examine the validity of scores on the SPQ and other schizotypy measures and their variation or consistency across cultures.

Association between attachment prototypes and schizotypy dimensions in two independent non-clinical samples of Spanish and American young adults.

Attachment theory offers a powerful theoretical framework for elucidating the developmental pathway through which childhood interpersonal trauma confers vulnerability to psychosis. In the present study, the association between attachment and schizotypy was explored in two independent non-clinical samples of Spanish (n=547) and American (n=1425) young adults. Participants completed the Relationship Questionnaire and the Wisconsin Schizotypy Scales. Following attachment theory and cognitive accounts of psychosis, it was hypothesized that preoccupied attachment would be associated with positive schizotypy, dismissing attachment with negative schizotypy, and fearful attachment with both schizotypy dimensions. Results confirmed these predictions, thus supporting the theoretical frameworks invoked. Also, the associations found in these non-clinical samples are consistent with those in clinical psychosis, supporting the continuum model of schizotypy and schizophrenia. Finally, there was cross-cultural consistency of these associations. Overall, the findings support the application of attachment theory for furthering our understanding of whether different insecure styles, characterized by different self and other representations and affect regulation strategies, play a role in the pathways to positive and negative symptoms.

Heritability and longitudinal stability of schizotypal traits during adolescence.

The study investigated the genetic and environmental etiology of schizotypal personality traits in a non-selected sample of adolescent twins, measured on two occasions between the ages of 11 and 16 years old. The 22-item Schizotypal Personality Questionnaire- Child version (SPQ-C) was found to be factorially similar to the adult version of this instrument, with three underlying factors (Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). Each factor was heritable at age 11-13 years (h (2) = 42-53%) and 14-16 years old (h (2) = 38-57%). Additive genetic and unique environmental influences for these three dimensions of schizotypal personality acted in part through a single common latent factor, with additional genetic effects specific to both Interpersonal-Affective and Disorganization subscales at each occasion. The longitudinal correlation between the latent schizotypy factor was r = 0.58, and genetic influences explained most of the stability in this latent factor over time (81%). These longitudinal data demonstrate significant genetic variance in schizotypal traits, with moderate stability between early to middle adolescence. In addition to common influences between the two assessments, there were new genetic and non-shared environmental effects that played a role at the later assessment, indicating significant change in schizotypal traits and their etiologies throughout adolescence.

Schizotypy and handedness in Japanese participants, revisited.

Although previous studies have suggested a relationship between mixed-handedness and schizotypic symptoms, possibly indicating a predisposition to schizophrenia, the participants involved were exclusively from Western cultures. Only two reports have examined the relationship between handedness and schizotypy in Asian cultures, and both of these studies failed to show a significant association between mixed-handedness and schizotypy, possibly due to cultural pressures against left-handedness. In the present study we examined the relationship between handedness and schizotypy among Japanese participants (N=231, study 1; N=274, study 2). In order to avoid cultural biases, we used a modified handedness scale in addition to the traditional scale developed in Western cultures. As a result, we show for the first time that mixed-handed Japanese participants have the strongest schizotypal traits, particularly positive schizotypic traits (p<.05). These results suggest that positive schizotypal traits may be universally associated with mixed-handedness or atypical cerebral lateralisation, even in non-Western cultures.

Over-representation of Maori New Zealanders among adolescents in a schizotypy taxon.

BACKGROUND: Minority ethnic and migrant groups are often over-represented among those with schizophrenia. OBJECTIVES: The aim of this study was to determine whether Maori, the aboriginal minority of New Zealand, are over-represented in a schizotypy taxon derived from a general population sample of adolescents. METHOD: Secondary school students (n = 387) aged 13 to 17 years completed self-report measures of four schizotypy attributes, magical thinking, hallucinatory tendency, self-referential ideation, and perceptual aberration, and indicated ethnic descent and self-identified ethnic belonging. RESULTS: Taxometric analyses (maximum covariance, maximum eigenvalue, latent modes) yielded consistent evidence of taxonicity of schizotypy. Participants who were of Maori descent were over-represented in the schizotypy group. CONCLUSIONS: Ethnicity, or the stress and resilience factors for which ethnicity is a proxy measure, has a measurable impact on psychometric risk for schizophrenia.

Correlation between P50 suppression and psychometric schizotypy among non-clinical Japanese subjects.

The link between P50 suppression and psychometric schizotypy was previously reported in non-clinical English-speaking subjects; however, whether a similar relationship exists within a different ethnic sample is unknown. Furthermore, whether such a relationship can also be accounted for by such basic personality characteristics as extraversion or neuroticism has not yet been reported. In the present study, we investigated the correlations of P50 suppression with psychometric schizotypy, and with extraversion or neuroticism among non-clinical Japanese. Subjects were 34 healthy volunteers. The auditory P50 potential was obtained using a paired stimulus paradigm. Psychometric schizotypy was assessed using schizotypal personality questionnaire (SPQ). Extraversion and neuroticism were assessed using Maudsley personality inventory (MPI). P50 suppression correlated not only with total SPQ score, but also with extraversion and with neuroticism. However, the partial correlation analysis revealed a significant partial correlation of P50 suppression with SPQ when controlled for extraversion or neuroticism, and a non-significant partial correlation of P50 suppression with extraversion or neuroticism when controlled for SPQ. When subjects were divided into two subgroups according to the mean SPQ score, the degree of P50 suppression was lower in the high than in the low SPQ scorers. Our results indicate that P50 suppression is one of the neurobiological substrates underlying psychometric schizotypy, and that this relationship cannot be accounted for by measures of extraversion or neuroticism.

Handedness and schizotypy in a Japanese sample: an association masked by cultural effects on hand usage.

Previous research has shown a robust association between schizotypy and mixed/ambiguous-handedness, but little is known about the universality of this relationship outside Western cultures. The present paper examines this issue in a sample of 413 Japanese students administered (in Japan) the Annett handedness questionnaire and a schizotypy scale (STA). Conventional analyses of current hand preference, using several indices derived from the Annett scale, mostly failed to replicate previous findings. However, there was a significant tendency for greater use of either hand in highly schizotypal males. Furthermore, a significant association between schizotypy and non-right-handedness was found--again only in males--after correcting for the effects of early switching of hand usage, presumed to be due to cultural pressure against left-handedness in Japanese society. These results were found to be highly convergent with findings previously reported for clinical schizophrenia.

Schizotypy in community samples: the three-factor structure and correlation with sustained attention.

The authors examined cross-cultural applicability of the Schizotypal Personality Questionnaire (SPQ), the Perceptual Aberration Scale (PAS), and the Continuous Performance Test in community samples of Taiwanese adults and adolescents. The authors tested hypotheses that a 3-factor structure of the SPQ (Cognitive-Perceptual, Interpersonal, and Disorganization: A. Raine et al., 1994) exists for both samples and that the Interpersonal factor is associated with poorer attention. The authors replicated the 3-factor model for both samples, and they externally validated the model in adults: The Interpersonal factor and possibly the Disorganization factor were associated with poorer attention, whereas the Cognitive-Perceptual factor was not. The PAS differed from the Cognitive-Perceptual factor in its consistent association with poorer attention in both samples. These have important implications for the scales in the early detection of the schizotypy in various cultures.