Journal of Abnormal Psychology

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1 Journal of Abnormal Psychology General Personality and Psychopathology in Referred and Nonreferred Children and Adolescents: An Investigation of Continuity, Pathoplasty, and Complication Models Marleen De Bolle, Wim Beyers, Barbara De Clercq, and Filip De Fruyt Online First Publication, March 26, doi: /a CITATION De Bolle, M., Beyers, W., De Clercq, B., & De Fruyt, F. (2012, March 26). General Personality and Psychopathology in Referred and Nonreferred Children and Adolescents: An Investigation of Continuity, Pathoplasty, and Complication Models. Journal of Abnormal Psychology. Advance online publication. doi: /a

2 Journal of Abnormal Psychology 2012 American Psychological Association 2012, Vol., No., X/12/$12.00 DOI: /a General Personality and Psychopathology in Referred and Nonreferred Children and Adolescents: An Investigation of Continuity, Pathoplasty, and Complication Models Marleen De Bolle, Wim Beyers, Barbara De Clercq, and Filip De Fruyt Ghent University This study investigated the continuity, pathoplasty, and complication models as plausible explanations for personality-psychopathology relations in a combined sample of community (n 571) and referred (n 146) children and adolescents. Multivariate structural equation modeling was used to examine the structural relations between latent personality and psychopathology change across a 2-year period. Item response theory models were fitted as an additional test of the continuity hypothesis. Even after correcting for item overlap, the results provided strong support for the continuity model, demonstrating that personality and psychopathology displayed dynamic change patterns across time. Item response theory models further supported the continuity conceptualization for understanding the association between internalizing problems and emotional stability and extraversion as well as between externalizing problems and benevolence and conscientiousness. In addition to the continuity model, particular personality and psychopathology combinations provided evidence for the pathoplasty and complication models. The theoretical and practical implications of these results are discussed, and suggestions for future research are provided. Keywords: development, personality and psychopathology, pathoplasty model, complication model, continuity model, children and adolescents Supplemental materials: Marleen De Bolle, Wim Beyers, Barbara De Clercq, and Filip De Fruyt, Department of Developmental, Personality and Social Psychology, Ghent University. We thank Robert F. Krueger, Douglas B. Samuel, and Jaime Derringer for their suggestions and help with the IRT analyses and we thank Lena C. Quilty and Kristian E. Markon for proofreading the manuscript. We also thank the children, adolescents, and their mothers for kindly volunteering to participate in the study. Filip De Fruyt receives royalties for the HiPIC measure. Correspondence concerning this article should be addressed to Marleen De Bolle, Department of Developmental, Personality, and Social Psychology, Ghent University, Faculty of Psychology and Educational Sciences, Henri Dunantlaan 2, 9000 Ghent, Belgium. Marleen.DeBolle@UGent.be Four different models have gained consensus in the literature as plausible etiological explanations for the relations between general personality and psychopathology. The predisposition/vulnerability model states that the presence of particular personality traits increases the probability of developing a clinical disorder. In contrast, the complication/scar model posits that an existing Axis I disorder may cause changes in personality. According to the pathoplasty/exacerbation model, co-occurring general personality traits and Axis I pathology may have an independent etiology and onset, but personality can influence the course or manifestation of an Axis I disorder. Finally, the spectrum or shared factor model assumes that personality traits and Axis I disorders form a spectrum ranging from general traits to subclinical characteristics to full-blown psychopathology because of shared underlying etiological factors (Krueger & Tackett, 2003; Mineka, Watson, & Clark, 1998). The latter model is closely connected to the continuity model, referring to the systematic phenomenological covariation of personality and psychopathology within and across time, without pronouncing upon etiology or causality of this covariation (see for instance Shiner (2000) for continuity assumptions between childhood personality and [mal]adaptation). As such, the continuity hypothesis can be considered a prerequisite condition of the spectrum hypothesis. Research has demonstrated that these models are not mutually exclusive, and all have received at least some support (Widiger, Verheul, & van den Brink, 1999). More specifically, it has been argued that all are potentially applicable within a single individual to some degree (Millon & Davis, 1996), and that different models perhaps explain different classes of disorder (Dolan-Sewell, Krueger, & Shea, 2001). Thus far, these models have been primarily examined in isolation. More integrative models for framing personalitypsychopathology relations such as those proposed for adults are not yet empirically examined in younger age groups. The study presented here addresses this integrative perspective and simultaneously investigates three explanatory models in community and referred children and adolescents by means of multivariate structural equation modeling and item response theory analyses. Integrative Models on Personality and Psychopathology Clark (2005) recently integrated the different hypotheses regarding personality-psychopathology relations in a comprehensive hi- 1

3 2 DE BOLLE, BEYERS, DE CLERCQ, AND DE FRUYT erarchical model, postulating that adult personality traits and psychopathological syndromes or disorders emerge through the differential activity of three innate biobehavioral dimensions: two affective systems positive and negative affectivity and a third regulatory system, labeled (dis)inhibition. Earlier, Krueger and Tackett (2003) outlined an empirically based, hierarchical descriptive system for the more prevalent mental disorders, providing a series of hypotheses regarding the particular nature of personalitypsychopathology relations. This model introduces the internalizing and externalizing spectra as overarching dimensions that can further be decomposed into four to five lower-order dimensions resembling those that comprise the Five Factor Model (FFM; McCrae & Costa, 1999). More specifically, neuroticism and extraversion are primarily linked with the internalizing spectrum whereas agreeableness and conscientiousness are primarily associated with the externalizing spectrum. Neuroticism has also been related to internalizing and externalizing behaviors or disorders (e.g., Keiley, Lofthouse, Bates, Dodge, & Pettit, 2003; Lilienfeld, 2003), suggesting that this personality dimension is mainly responsible for the often found correlation between the internalizing and externalizing dimensions. Although Clark (2005) and Krueger and Tackett (2003) argued that the empirical connection between personality and psychopathology is mostly consistent with the continuity/spectrum hypothesis, they agree that there may be other relevant etiological models (i.e., the vulnerability, complication/ scar, or pathoplasty/exacerbation model) that augment and extend the spectrum or shared factor model. These integrative models are largely derived from evidence pertaining to the personality and psychopathological features observed in adult samples. Despite the growing evidence for robust associations between personality traits and mental disorders in children (Tackett, 2006), relatively little is known about how these findings can be integrated into the hierarchical integrative models proposed for adults. However, there is mounting evidence that many, if not most, lifetime psychiatric disorders first appear in childhood (Rutter, Kim-Cohen, & Maughan, 2006), with most childhood emotional and behavioral problems displaying a similar metastructure of the internalizing and externalizing dimensions of psychopathology (Achenbach, 1991). In addition, there is convincing evidence that the FFM dimensions of personality observed in adulthood are also reliable and valid indicators of personality differences in childhood and adolescence (Caspi & Shiner, 2006; De Fruyt et al., 2006; John, Caspi, Robins, Moffitt, & Stouthamer- Loeber, 1994), introducing a common language to conceptualize personality across the life span (Tackett, 2006). This common structure of personality and psychopathology across childhood and adulthood facilitates research on the nature of their interrelations from childhood onward within a single framework, building upon the established conceptual models of personality-psychopathology associations (e.g., Krueger & Tackett, 2003). Empirical Findings on the Nature of Personality- Psychopathology Associations During the last decade, researchers have moved from identifying relations between personality traits and types of psychopathology toward exploring the nature of these relations. Most research has focused on a vulnerability approach to conceptualize personalitypsychopathology relations in children and adolescents (Tackett, 2006), identifying low conscientiousness (Lynam et al., 2000), low affiliation (i.e., agreeableness, Nigg, 2006), extreme low levels of approach (i.e., extraversion, Nigg, 2006), and high neuroticism (Eisenberg et al., 2000; Gjone & Stevenson, 1997) as potentially relevant personality risk factors for the development of externalizing pathology, whereas behavioral inhibition (a combination of high neuroticism and low extraversion) acts as a risk factor for internalizing pathology (for a review, see Hirshfeld-Becker et al., 2003). A different set of studies supports the pathoplasty model by demonstrating that personality predicts subsequent problem behavior (Gjone & Stevenson, 1997; Huey & Weisz, 1997; Kerr, Tremblay, Pagani, & Vitaro, 1997). van den Akker et al. (2010) found that adolescents may develop internalizing problems if they decrease in extraversion and emotional stability during the transition to adolescence. Furthermore, decreases in benevolence (this factor covers agreeableness traits and the manageability of children, Mervielde & De Fruyt, 2002), conscientiousness, and emotional stability predicted later externalizing problems. Other studies suggest that childhood psychopathology may cause personality change later in life, supporting the complication hypothesis. For example, Shiner, Masten, & Tellegen (2002) found that childhood antisocial behavioral problems predicted an increase in neuroticism in adulthood. Studies supporting the continuity hypothesis (e.g., Ehrler, Evans, & McGhee, 1999; Roberts, Jackson, Burger, & Trautwein, 2009) have linked internalizing problems to high neuroticism and low extraversion (Anderson & Hope, 2008; Griffith et al., 2010), although there is also research in childhood showing moderately negative associations with benevolence (Mervielde, De Clercq, De Fruyt, & Van Leeuwen, 2005). Considerable evidence suggests that various externalizing behaviors are associated with low agreeableness, low conscientiousness, and, to a lesser extent, high neuroticism (John et al., 1994; Miller & Lynam, 2001; Trull & Sher, 1994). Furthermore, it can be concluded from multiple studies across different nations and research groups that the phenotypic association between personality and psychopathology is undergirded by genetic coherence, providing support for the continuity/spectrum explanatory model of personality-psychopathology associations (Krueger, Markon, Patrick, & Iacono, 2005). For instance, twin studies have identified a common underlying genetic influence accounting for the phenotypic correlation over time between externalizing problems on the one hand and personality traits such as neuroticism (e.g., Gjone & Stevenson, 1997), disinhibition (e.g., Krueger et al., 2002), negative emotionality (neuroticism, combined with irritability) (Singh & Waldman, 2010; Schmitz et al., 1999), and conscientiousness (Roberts et al., 2009) on the other. Furthermore, shared genetic determinants of neuroticism, extraversion, and internalizing disorders have been well documented (Bienvenu, Hettema, Neale, Prescott, & Kendler, 2007). Although this wealth of research has enhanced our understanding of personality-psychopathology associations, a significant limitation of existing work entails frequent neglect of the continuity/ spectrum model. Indeed, presumed evidence for the vulnerability, complication, or pathoplasty models can also be accounted for by the continuity/spectrum model (Krueger & Tackett, 2003). Therefore, none of the currently available studies on cross-sectional and longitudinal associations between the FFM personality dimensions

4 DEVELOPMENT OF PERSONALITY AND PSYCHOPATHOLOGY 3 and internalizing and/or externalizing problems in childhood or adolescence have disentangled vulnerability, pathoplasty, complication, or continuity effects, hampering the evaluation of the specificity of the personality-psychopathology relations (Tackett, 2006) and pointing toward the relevance of simultaneously testing these competing theoretical models. Current Study The work presented here aims to refine our understanding of the nature of personality-psychopathology relations by simultaneously considering the pathoplasty, complication, and continuity explanatory mechanisms and relying on comprehensive dimensional measures of childhood personality and psychopathology. Parallel to assumptions on adult personality-psychopathology associations (Clark, 2005; Krueger & Tackett, 2003), we hypothesize that the nature of the personality-psychopathology relations at a young age is also consistent with the continuity hypothesis. On the basis of evidence generated from genetically informative studies, we expect to find negative continuity associations for externalizing psychopathology with emotional stability, benevolence, and conscientiousness and for internalizing psychopathology with emotional stability and extraversion. As outlined above, Clark (2005); Krueger & Tackett (2003); and Krueger et al. (2005) posit in addition that personality and psychopathology are hierarchically structured, including stronger associations between dimensions of psychopathology and traits that unfold from a similar higher-order construct (i.e., the positive and negative affectivity and [dis]inhibition constructs in Clark s model or the broad superfactors of internalization and externalization in Krueger s model). Studies on the personality-psychopathology link in children and adolescents accordingly find conscientiousness and agreeableness/benevolence to be more strongly related to externalizing behavior, whereas neuroticism and extraversion are especially related to internalizing behavior (Van Leeuwen, Mervielde, De Clercq, & De Fruyt, 2007). Some studies also illustrated that neuroticism is meaningfully linked to the internalizing and externalizing psychopathology dimensions (Keiley, Lofthouse, Bates, Dodge, & Pettit, 2003; Lilienfeld, 2003). From these findings, we expect that emotional stability will show meaningful relations with internalizing and externalizing syndromes, albeit we assume that this personality dimension, just like extraversion, will show stronger continuity associations with internalizing than with externalizing pathology. Likewise, we hypothesize that agreeableness/benevolence and conscientiousness will show significantly stronger continuity associations with externalizing psychopathology. We further hypothesize that complication and pathoplasty models will form secondary explanatory models of personalitypsychopathology relations, with a varying significance depending on the particular personality-pathology combination under consideration. To our knowledge, no study has investigated these causal longitudinal personality-psychopathology relations while taking into account continuity associations; thus, no specific hypotheses regarding expected complication or pathoplasty effects are postulated. 1 Research on personality-psychopathology relations has been criticized by stating that these associations may primarily result from item overlap, thereby referring to the issue that measures assessing distinct theoretical constructs may include items with an identical or similar content, resulting in contamination of measures (American Educational Research Association, American Psychological Association, & National Council on Measurement in Education, 1999). Therefore, the study presented here will examine these longitudinal personality-psychopathology relations before and after correction for item overlap, taking into account a conceptual and an empirical evaluation of item overlap. A conceptual evaluation of item overlap entails an expert perspective on the representativeness of items for both constructs (e.g., Lemery, Essex, & Smider, 2002; Lengua, West, & Sandler, 1998). An empirical evaluation of item overlap involves a joint confirmatory factor analysis of items that comprise the personality and psychopathology constructs under consideration (e.g., De Clercq, Van Leeuwen, De Fruyt, Van Hiel, & Mervielde, 2008; Lemery, Essex, & Smider, 2002; Lengua, West, & Sandler, 1998). On the basis of previous studies (Prinzie, Onghena, & Hellinckx, 2005; Van Leeuwen, unpublished manuscript), we expect that item overlap will not substantially alter the conclusions regarding the nature of the personality-psychopathology relations considered in the present manuscript. Method Participants and Procedure Data were collected from a community and a referred sample of children in the course of the Personality and Affect Longitudinal Study (PALS). Participants were recruited at baseline (time 1; T1) by third-year undergraduate psychology students of Ghent University and follow-up assessments were conducted via mail 1 (time 2; T2) and 2 years (time 3; T3) after initial assessment. Children had to be between 8 and 14 years old with Dutch as the native language of mother and child. Exclusion criteria included the presence of (a) a mental (e.g., mental retardation) and/or (b) any physical constraints or disabilities. Data collection was approved by the Ghent University Ethical Review Board. All participants were assured that the information would be treated as confidential and would only serve research purposes. Written informed consent was obtained from all mothers and children in both samples. The combined community and referred sample consisted of 717 children (54.4% girls) aged from 8 to 14 years (M 10.74, SD 1.37). Community sample. Students were instructed to recruit a child from the general population in their own network after detailed information regarding study aims, procedure, and ethics of data collection was provided. Students visited the families at home and asked the mother and child to complete a set of questionnaires in two separate rooms to ensure that their independent opinion was assessed. Students were instructed not to assist participants and 1 The predisposition model was not evaluated because personality was not measured systematically before the onset of psychopathology symptoms. A proxy investigation of the predisposition model would be to investigate personality differences between individuals from the population sample who developed clinical syndrome scores at T2 or T3 and individuals with nonclinical scores at all three measurement occasions. However, because of the very low base rates of individuals in the community sample scoring beyond clinical cutoffs for internalizing or externalizing problems, such analyses were not possible with the sample presented here.

5 4 DE BOLLE, BEYERS, DE CLERCQ, AND DE FRUYT were only allowed to explain the meaning of item wordings that were not clear to the mother or child. In total, 571 community children (55% girls; mean age 10.70, SD 1.23) were recruited. The response rates were 71.8% for T2 and 65.5% for T3. Clinically referred sample. The first author selected mental health service providers from an online directory of registered providers of psychological care in Flanders to ensure a broad geographical coverage. Students were provided with contact information of a particular service and were instructed to contact this service by telephone and to explain study aims, procedures, and ethics of data collection. All children (n 146; 52.1% girls; mean age years, SD 1.84) were assigned a clinical status at the moment of inclusion in PALS. When psychologists of the particular service agreed to participate, the first child (and its parents) on the psychologist s appointment schedule that qualified for the study was asked to take part in the current research. Parents and child were given a set of inventories, consent forms, and information letters and were asked to return the completed questionnaires at the next appointment in a sealed envelope that was directly forwarded to the researchers. At T1, 11.3% of the referred children were situated in the intake phase, 20.3% received psychological advice or further orientation, 63.2% received psychotherapy, and 5.3% visited the mental health center because of persisting or recurring problems. See supplemental material for an overview of the primary reason for referral. The response rates of the follow-up assessments were 82.9 and 68.5% for T2 and T3, respectively. Measures Psychopathology. Mothers completed the Dutch version of the Child Behavior Checklist (CBCL; Verhulst, Van der Ende, & Koot, 1996) at each assessment period to evaluate their child s behavioral and emotional problems in the past 6 months. The CBCL contains 113 items that are scored on a 3-point scale (0 not true,1 somewhat or sometimes true,2 very or often true). Two empirically derived broadband scales can be computed: internalizing problems (including the anxiety/depression, somatic complaints, and social withdrawal syndrome scales) and externalizing problems (including the delinquent behavior and aggressive behavior syndrome scales). The Cronbach values for internalizing and externalizing problems were.91 and.90 at T1,.91 and.92 at T2, and.92 and.94 at T3, respectively. General personality. Mothers completed the Hierarchical Personality Inventory for Children (HiPIC; Mervielde, De Fruyt, & De Clercq, 2010) at each assessment period to assess their child s general personality. It includes 144 items grouped into 18 facets (with eight items each) that are hierarchically organized under the five higher-order factors of emotional stability, extraversion, imagination, benevolence, and conscientiousness. These factors are conceptually and empirically strongly related to the FFM factors assessed in adults. The benevolence factor is defined broadly in content because it captures traits referring to the manageability of children in addition to agreeableness traits, whereas the imagination factor represents openness and intellect traits. In the study presented here, adequate to good internal consistencies were obtained for the HiPIC domains: Cronbach s values ranged from.73 (extraversion) to.85 (emotional stability) at T1, from.74 (extraversion) to.85 (benevolence) at T2, and from.75 (extraversion) to.88 (conscientiousness) at T3. Statistical Analyses Figure 1 depicts a conceptual multivariate latent change model (LCM) linking the developmental pattern of internalizing and externalizing problems to developments in emotional stability. As illustrated in Figure 1, evidence for the pathoplasty, complication, and continuity models will be investigated simultaneously. 1 Because the within-time correlation between personality and psychopathology at initial assessment may also reflect persisting vulnerability effects, we will only consider correlated change between personality and psychopathology as empirical evidence for the continuity model. Preparatory to fitting the LCMs, the measurement models were estimated for the latent constructs of interest using exploratory structural equation modeling (ESEM). The ESEM approach differs from the typical confirmatory factor analysis approach in that all factor loadings are estimated for each measurement occasion, subject to constraints, so that the model can be identified (Asparouhov & Muthén, 2009). To obtain independent personality factors, ESEM analysis was performed on the 18 HiPIC facets measured at T1, T2, and T3, with orthogonal rotation. Furthermore, an ESEM analysis was performed on the CBCL data 2 with oblique rotation. In both ESEM analyses, longitudinal measurement invariance was assumed. The ESEM factor scores for emotional stability, extraversion, benevolence, conscientiousness, imagination, internalizing, and externalizing problems were saved and used as single indicators in the multivariate LCMs for the respective factors. The error variances of these indicators were fixed to zero to identify the models. In total, five multivariate LCMs were estimated, each combining one personality factor with internalizing and externalizing problems. In these multivariate LCMs, we controlled for age, sex, clinical status, and the covariation between internalizing and externalizing problems across time. By considering orthogonal personality factors in the multivariate LCMs, problems of dependency between the results of the five multivariate LCMs were excluded. Missing data 3 were accommodated in all models using FIML under the assumption of missingness at random (cf., Allison, 2003). 2 Because an ESEM analysis on the internalizing and externalizing syndrome scales scores did not converge, the ESEM analyses for the CBCL were performed on parcels. More specifically, three parcels per syndrome scale were constructed by applying the item-to-construct balancing technique (Little, Cunningham, Shahar, & Widaman, 2002) to the items of each syndrome. 3 The personality dimensions and psychopathology syndromes are not directly observable variables but are measured indirectly by means of several (behavioral) items. In fact, these items first cluster together in more fine-grained personality facets or psychopathology syndromes, which in turn load on their higher-order personality dimensions (emotional stability, extraversion, conscientiousness, benevolence, or imagination) or psychopathology dimension (internalizing or externalizing). Therefore, to investigate whether the constructs extraversion and internalizing pathology, for instance, both reflect the same underlying latent trait as stated by the continuity hypothesis we included the four extraversion facet and the three internalizing syndrome scores in the IRT analyses, not the individual items that measure these facets or syndromes.

6 DEVELOPMENT OF PERSONALITY AND PSYCHOPATHOLOGY 5 Figure 1. Conceptual LCM linking internalizing and externalizing problems to emotional stability. Note. T1 first measurement occasion; T2 second measurement occasion; T3 third measurement occasion; INT internalizing problems; EXT externalizing problems; ES emotional stability; PE personality trait (i.e., ES in the present example); PP psychopathology (i.e., INT and EXT in the present example). The paths A, A, B, B, C, and C represent the autoregressive paths for changes in INT, ES, and EXT respectively. For example, A reflects whether children s INT level at T1 predicts change in INT from T1 to T2, whereas A reflects whether change in INT from T1 to T2 is predictive of change in INT from T2 to T3. Paths PE T1 PP T1,PE 12 PP 12, and PE 23 PP 23 reflect the continuity hypothesis because they encompass that (changes in) INT and/or EXT and ES are related across time. These paths are corrected for covariation between INT and EXT (i.e., paths PP T1 PP T1,PP 12 PP 12, and PP 23 PP 23 ). However, because the PE T1 PP T1 path may reflect the persistence of a vulnerability effect, only PE 12 PP 12 and PE 23 PP 23 will be considered as evidence of the continuity model. Paths PP T1 3PE 12, and PP 12 3PE 23 are informative about the complication hypothesis, reflecting an effect of INT/EXT or change in INT/EXT on subsequent change in ES. Paths PE T1 3PP 12, and PE 12 3PP 23 display the pathoplasty hypothesis, encompassing that personality (ES) affects the subsequent development of INT/EXT. In addition, item response theory (IRT) analyses were performed for those personality-psychopathology continuity associations that were supported by the multivariate LCMs to directly test whether the personality and psychopathology factors under consideration reflect the same underlying dimension with the psychopathology factor assessing the more maladaptive part of the distribution. For these IRT analyses, we included the HiPIC facets and those CBCL syndrome scores that comprise the internalizing and externalizing scales rather than the individual items as observed variables. For instance, the IRT model for extraversion and internalizing pathology included the four extraversion facet scores together with the three internalizing syndrome scores as indicators of a single latent factor. 3 Because it is unclear how to best estimate nonconstant test information for continuous variables, and because standard IRT methods require discrete variables, the mean CBCL syndrome scores and the mean HiPIC facet scores were recoded into three-category variables. 4 IRT analyses were performed on these discrete variables. All analyses were performed using Mplus, version 5.1.(Muthén & Muthén, ). In addition to 2, the comparative fit index (CFI) and the standardized root mean square residual (SRMR) were reported for the ESEM analyses and the LCMs. For the IRT analyses, CFI and the Tucker Lewis index (TLI) were reported. CFI and TLI values above.90 indicate a good fit and values above.95 indicate excellent fit (Steiger, 1990). SRMR 4 Mothers were asked to rate the CBCL items on a scale from 0 to 2, with 0 not true, 1 somewhat or sometimes true, and 2 very or often true. Likewise, mothers were asked to evaluate how characteristic each HiPIC item was for their child, with 1 hardly characteristic, 2 little characteristic,3 more or less characteristic,4 characteristic, and 5 very characteristic. These mean CBCL syndrome and HiPIC facet scores were categorized, taking into account the labels attached to the item scores and current round-off rules: CBCL score.50 category 0;.50 CBCL score 1.50 category 1; CBCL score 1.50 category 2. HiPIC score 2.50 category 0; 2.50 HiPIC score 3.50 category 1; HiPIC score 3.50 category 2. As such, three response categories for the CBCL syndrome scores and HiPIC facet scores were obtained, with 0 not true, 1 somewhat or sometimes true, 2 very or often true.

7 6 DE BOLLE, BEYERS, DE CLERCQ, AND DE FRUYT scores below.10 are considered acceptable and scores below.05 are indicative of good fit (Ullman, 2001). As outlined in the introduction, these analyses were performed before and after correction for item overlap, thereby taking into account a conceptual and an empirical evaluation of item overlap. We applied the findings of Van Leeuwen (unpublished manuscript) to identify problematic HiPIC and CBCL items. In this study, expert ratings (i.e., conceptual perspective) on item overlap were obtained conform to the procedure of Lengua, West, and Sandler (1998) and Lemery, Essex, and Smider (2002). More specifically, experts were asked to rate the indicative value of each HiPIC and CBCL item in terms of representing a personality or psychopathology descriptor by means of a 5-point scale, with 1 item is a much better measure of personality than psychopathology, 2 item is a somewhat better measure of personality than psychopathology, 3 item is not a better measure for one of both constructs, 4 item is a somewhat better measure of psychopathology than personality, and 5 item is a much better measure of psychopathology than personality. One-sample t tests were conducted with a score of 3 (item is not a better measure for one of both constructs) as the test value against which the mean expert rating for each item was tested. Items with a significant t value indicating a significant difference from the neutral point of 3 in the wrong direction were eliminated. Empirical evaluation of content overlap was done by means of a joint confirmatory factor analysis (CFA) of the items that comprise the HiPIC and CBCL constructs under consideration. More specifically, a total of 10 CFAs (5 personality dimensions 2 broadband problem scales) were conducted. The following criteria were used for identifying and eliminating overlapping items: (a) cross-loadings larger than.30, (b) low factor loadings (.30) on both constructs, (c) error correlations across factors greater than.20, and (d) an item s error of measurement correlated with 20% or more of the item errors from the other factor at an absolute value of r.15 or higher. Five HiPIC and six CBCL items were omitted based on conceptual grounds, whereas 20 HiPIC and 14 CBCL items were omitted based on the empirical evaluation of item overlap (see supplemental material). For details regarding the sample and procedure, see Van Leeuwen (unpublished manuscript). Results ESEM The results of the ESEM analyses on the 18 HiPIC facets indicate an overall good fit to the data ( , df 1192, p.000; SRMR.04; CFI.97). A clear five-factor orthogonal structure emerges across the three measurement occasions, with all of the subscales loading primarily on their assumed higher-order factor. The five orthogonal factors are benevolence, conscientiousness, emotional stability, extraversion, and imagination, respectively. The results of the ESEM analyses on the CBCL data indicate an overall good fit ( , df 898, p.000; SRMR.05; CFI.92). A clear two-factor oblique structure emerges, with all of the parcels showing primary loadings on their higher-order dimension. The two oblique factors are internalizing and externalizing problems. 2 After controlling for item overlap, the results of the ESEM analyses indicate a good fit, with a clear five-factor orthogonal structure emerging for the HiPIC data ( , df 1192, p.000; SRMR.04; CFI.97 and , df 1192, p.000; SRMR.04; CFI.97 for the conceptual and empirical perspective on item overlap, respectively) and a clear two-factor oblique structure emerging for the CBCL data ( , df 63, p.000; SRMR.04; CFI.98 and , df 63, p.000; SRMR.03; CFI.98 for the conceptual and empirical perspective on item overlap, respectively) across the three measurement occasions. All factors covered identically the same content as in the noncorrected data, with all of the indicators loading primarily on their assumed higher-order factor. Multivariate LCMs Results of the multivariate LCMs are summarized in Table 1. The continuity model receives overall strong support by the data because psychopathology and personality generally show associated change across time. More specifically, change in emotional stability and benevolence is negatively related to change in internalizing and externalizing problems. Change in extraversion is negatively related to change in internalizing and to a lesser extent to change in externalizing problems. Change in conscientiousness and imagination is exclusively related to change in externalizing problems. In addition, we compared the strength of the continuity associations for internalizing versus externalizing psychopathology by comparing the mean latent change correlation (i.e., averaged across change from T1 to T2 and from T2 to T3) of internalizing and externalizing psychopathology in relation to each personality trait separately using the z statistic. As hypothesized, emotional stability (z 2.87, p.01) and extraversion (z 2.29, p.01) demonstrate stronger continuity associations with internalizing pathology than with externalizing pathology, whereas benevolence (z 3.96, p.001) demonstrates stronger continuity associations with externalizing than with internalizing problems. Nevertheless, substantial relations for emotional stability with internalizing and externalizing pathology are observed, supporting the idea that this personality dimension might be responsible for the often-found co-occurrence of internalizing and externalizing problems. The continuity associations with imagination are significantly larger for externalizing than for internalizing pathology (z 3.72, p.001), whereas the associated change with conscientiousness did not significantly differ between internalizing and externalizing pathology (z 0.85, p.05). The complication and pathoplasty hypotheses received more focused support. When considering the complication effects, we see that emotional stability is only affected by internalizing pathology, whereas extraversion and benevolence are only affected by externalizing pathology. Conscientiousness and imagination appear to be affected by internalizing and externalizing problems. More specifically, when children display or develop more severe internalizing pathology, they subsequently become less emotionally stable (i.e., they become less self-confident and more prone to negative feelings). Children who have or develop more severe externalizing problems tend to become less benevolent (i.e., they become harder to manage in play and rearing and are more likely to approach social situations from their own perspective, without taking into account the interests of others) but more extraverted (i.e., they become less shy and more energetic). In addition, change

8 DEVELOPMENT OF PERSONALITY AND PSYCHOPATHOLOGY 7 Table 1 Fit Indices for the LCMs and Completely Standardized Parameter Estimates for the Structural Paths Estimated in the Total Sample (N 717) Continuity model Complication model Pathoplasty model PE PP 2 df SRMR CFI PE T1 PP T1 PE 12 PP 12 PE 23 PP 23 PP T1 3PE 12 PP 12 3PE 23 PE T1 3PP 12 PE 12 3PP 23 ES INT EXT E INT EXT B INT EXT C INT EXT I INT EXT Note. 2 2 statistic; df degrees of freedom; SRMR standardized root mean square residual; CFI comparative fit index; PE personality trait; PP psychopathology dimension; ES emotional stability; E extraversion; B benevolence; C conscientiousness; I imagination; INT internalizing problems; EXT externalizing problems. p.05. p.01. p.001. in conscientiousness is positively predicted by a preceding change in internalizing problems whereas it is negatively predicted by a preceding change in externalizing problems. Hence, as children develop more severe internalizing problems, they become more conscientious. However, as children develop more severe externalizing problems, they become less conscientious (i.e., they become less concentrated and orderly and may need more supervision and encouragement to complete tasks or assignments). Finally, (change in) internalizing problems positively predict(s) subsequent change in imagination, whereas change in imagination is negatively predicted by a preceding change in externalizing problems. This means that children who develop more severe internalizing problems appear to become more imaginative and better in approaching a problem from different angles. However, as children develop more severe externalizing problems, they may lose interests and curiosity, resulting in an unwillingness to learn new things. Most of the significant pathoplasty effects (3 of 4) involve benevolence and one involves extraversion. More specifically, initial levels of benevolence negatively influence subsequent change in internalizing and externalizing problems, whereas change in this personality trait negatively predicts subsequent change in internalizing pathology. This means that children who are less benevolent are more likely to develop internalizing and externalizing problems, and as they become less benevolent over time, they subsequently display more internalizing problems. Furthermore, extraversion has a pathoplasty effect on externalizing problems: Children who are more cheerful and social and are good in expressing their feelings tend to develop less externalizing problems. Two personality-psychopathology relations are characterized by more dynamic influential processes. More specifically, the relations between benevolence and externalizing problems display an exacerbating pattern: Suffering from externalizing problems likely leads to subsequent decrease in benevolence, which in turn results in an increasing level of externalizing problems. Furthermore, although children who score higher on extraversion are less likely to develop subsequent externalizing pathology, increases in externalizing pathology predict following increases in extraversion. The results of the LCMs after correction for item overlap from a conceptual or empirical perspective are provided as supplemental material. After controlling for item overlap, results regarding the continuity model remained the same, with the exception that the borderline significant associated change coefficient (from T1 to T2) between extraversion and externalizing problems became nonsignificant. Comparison of the strength of the continuity associations for internalizing versus externalizing psychopathology confirmed the significantly stronger continuity associations for internalizing pathology with emotional stability (z 4.06, p.001 and z 4.68, p.001 for item overlap corrected data on the basis of conceptual and empirical procedure, respectively) and extraversion (z 2.29, p.01 and z 2.39, p.01 for item overlap corrected data on the basis of conceptual and empirical procedure, respectively). Also, benevolence still demonstrated stronger continuity associations with externalizing than with internalizing problems, but only after correction for item overlap from an empirical perspective (z 2.28, p.01), and the continuity associations with imagination are significantly larger for externalizing than for internalizing pathology, but only after correction for item overlap from a conceptual perspective (z 2.19, p.01). Furthermore, conscientiousness now showed stronger continuity associations with externalizing than with internalizing problems (z 1.61, p.05 and z 1.61, p.05 for item overlap corrected data on the basis of the conceptual and empirical procedure, respectively). Again, more focused support was found for the pathoplasty and complication model after controlling for item overlap. More spe-

9 8 DE BOLLE, BEYERS, DE CLERCQ, AND DE FRUYT cifically, the pathoplasty effects from benevolence on internalizing and externalizing problems and the complication effects from externalizing problems on benevolence and from internalizing problems on emotional stability and imagination were confirmed. In addition, a pathoplasty effect from emotional stability on externalizing problems and a complication effect from externalizing problems on emotional stability emerged that was not found in the original analyses. The exacerbating pattern between benevolence and externalizing problems also emerged after controlling for item overlap. Furthermore, an exacerbating pattern between emotional stability and externalizing problems was identified, demonstrating that high levels of emotional stability are related to subsequent increases in externalizing pathology, which in turn leads to subsequent increases in emotional stability. IRT Analyses Unidimensionality verification. The results in Table 2 demonstrate that, at each measurement occasion, the assumption of unidimensionality holds for the models with internalizing problems in relation to emotional stability and extraversion and for the models with externalizing problems and benevolence. Unidimensionality is further evidenced for externalizing problems and conscientiousness at T1 and T2 and for externalizing problems and emotional stability at T1. After controlling for item overlap from a conceptual and an empirical perspective, unidimensionality was demonstrated for these very same personality-psychopathology combinations, except for the externalizing problems-emotional stability combination at T1 when correcting for item overlap from an empirical perspective (see supplemental material). For these models, the mean IRT parameters are subsequently calculated. IRT parameter estimation. Table 3 presents the mean IRT parameters for the particular HiPIC or CBCL constructs included in the respective IRT models without correction for item overlap. For instance, the mean IRT parameters for internalizing pathology and emotional stability (i.e., lines 1 and 2 in Table 3, respectively) were obtained by averaging the discrimination and difficulty parameters across the three categorized syndrome scores that comprise the internalizing scale and across the two categorized facet scores of emotional stability, respectively. Table 3 also includes Cohen s {1988} d effect sizes to compare the relative magnitude of the mean discrimination and difficulty parameters. To obtain these effect sizes, one-way analyses of variance were conducted within each of the IRT models such that indicators were treated as cases, each scale s membership (HiPIC vs. CBCL) was treated as the independent variable, and the discrimination or a difficulty parameter was the dependent variable (see Samuel, Simms, Clark, Livesley, & Widiger, 2010). The discrimination parameters reflect how much information the HiPIC facets and CBCL syndromes that are considered in tandem provide on average about the underlying latent trait (i.e., how good these indicators discriminate among individuals across the latent trait that underlies the personality and psychopathology constructs). Highly relevant to the continuity hypothesis are the difficulty parameters, which index the location along the latent trait where the HiPIC or CBCL indicators, included in the respective IRT models, are on average providing the most psychometric information. The difficulty parameters for threshold 1 show that the level of the latent trait at which the likelihood of responding a little or sometimes true becomes higher than that of responding not at all true is systematically higher for the CBCL than for the HiPIC indicators, which is fully consistent with the continuity hypothesis. In line, difficulty parameters for threshold 2 generally indicate that the latent trait at which the likelihood of responding frequently to very often true becomes higher than that of responding a little or sometimes true is consistently higher for the CBCL indicators than for the HiPIC indicators. For instance, Figure 2 displays the mean information curves for emotional stability and internalizing problems and clearly illustrates that internalizing problems are located at more extreme levels than emotional stability on the underlying latent variable, completely in line with the continuity hypothesis. After correcting for item overlap from a conceptual and empirical perspective, highly similar discrimination and difficulty parameters were obtained, confirming the general picture that internalizing or externalizing psychopathologies are located at more extreme levels on the underlying continuum compared with personality traits (see supplemental material). Discussion The study presented here is an attempt to provide an empirical basis for the validity of different etiological models that all take a unique perspective on the well-known associations between personality and psychopathology in childhood. The current work corroborates previous studies in this field that typically adopted a single model as a framework for understanding early personalitypsychopathology relations (for a review see Tackett, 2006) and is Table 2 Fit Indices for CFA Models for T1, T2, and T3 T1 T2 T3 Model 2 df CFI TLI 2 df CFI TLI 2 df CFI TLI INT ES INT E INT B EXT ES EXT B EXT C EXT I Note. T1 first measurement occasion; T2 second measurement occasion; T3 third measurement occasion. All HiPIC scales are reversed.

10 DEVELOPMENT OF PERSONALITY AND PSYCHOPATHOLOGY 9 Table 3 Mean IRT Model Parameter Estimates for T1, T2, and T3 Model Measurement occasion Difficulty Discrimination Threshold 1 Threshold 2 M SE M SE M SE INT ES T1 CBCL_INT HiPIC_ES T2 CBCL_INT HiPIC_ES T3 CBCL_INT HiPIC_ES INT E T1 CBCL_INT HiPIC_E T2 CBCL_INT HiPIC_E T3 CBCL_INT HiPIC_E EXT ES T1 CBCL_EXT HiPIC_ES EXT B T1 CBCL_EXT HiPIC_B T2 CBCL_EXT HiPIC_B T3 CBCL_EXT HiPIC_B EXT C T1 CBCL_EXT HiPIC_C T2 CBCL_EXT HiPIC_C Note. T1 first measurement occasion; T2 second measurement occasion; T3 third measurement occasion; INT Internalizing problems; EXT Externalizing problems; ES Emotional stability; E Extraversion; B Benevolence; C Conscientiousness; I Imagination. All HiPIC scales are reversed. Effect sizes are in italic. the first study that presents a joint examination of the continuity, pathoplasty, and complication models. By controlling for continuity effects when testing pathoplasty and complication effects, the study presented here is able to disentangle these specific models. The current design can be considered innovative because it includes comprehensive dimensional and age-specific childhood conceptualizations of personality and psychopathology and relies on multivariate LCM and IRT analyses. The most important finding of the study presented here can be situated along the evidence that the often neglected continuity model for explaining personality and psychopathology associations in childhood appears to be the most empirically supported model when simultaneously examining the validity of different models, even after controlling for item overlap. Indeed, most established associations between personality and psychopathology that were previously addressed from a single causal hypothesis, such as findings in support of the pathoplasty (e.g., Klimstra, Akse, Hale, Raaijmakers, & Meeus, 2010), vulnerability (e.g., Eisenberg et al., 2000; Lynam et al., 2000), or complication models (e.g., Shiner, Masten, & Tellegen, 2002), proved in our joint-model study to mainly result from a continuity model. This evidence is reflected in the convincing result that changes in all five personality factors were negatively associated with changes of internalizing and externalizing psychopathology and that internalizing and externalizing pathologies were found to be consistently located at more extreme levels on the underlying latent trait or continuum than personality traits. These results underscore the validity of previous work in adults that proposed the continuity model as the primary explanatory model of the personality-psychopathology association (e.g., Ehrler et al., 1999; Gjone & Stevenson, 1997; Roberts et al., 2009) and extend its applicability from adulthood toward children and adolescents.