Twins and the study of rater (dis)agreement.

Abstract

Genetically informative data can be used to address fundamental questions concerning the measurement of behavior in children. The authors illustrate this with longitudinal multiplerater data on internalizing problems in twins. Valid information on the behavior of a child is obtained for behavior that multiple raters agree upon and for rater-specific perception of the child's behavior. Rater-disagreement variance 2 (rd) accounted for 35% of the individual differences in internalizing behavior. Up to 17% of this 2 (rd) was accounted for by rater-specific additive genetic variance 2 (A u ). Thus, the disagreement should not be considered only to be bias/error but also as representing the unique feature of the relationships between that parent and the child. The longitudinal extension of this model helps to make a distinction between measurement error and the raters' unique perception of the child's behavior. For internalizing behavior, the results show large stability across time, which is accounted for by common additive genetic and common shared environmental factors. Rater-specific shared environmental factors show substantial influence on stability. This could mean that rater bias may be persistent and affect longitudinal studies. Genetically informative designs can be used to estimate the size of genetic and environmental effects on variation in behavior and other complex traits. It is less well known that these designs also have the potential to shed a unique light on fundamental measurement problems and could be an important addition to the traditional methodological arsenal for studying psychological data. This is illustrated in this article by studying sources of rater (dis)agreement in longitudinal data on internalizing problems in monozygotic (MZ) and dizygotic (DZ) twins rated at ages 3, 7, 10, and 12 years by their parents. Rater (Dis)agreementSelf-and observer ratings of behavior are important sources of information in psychology and psychiatry. It is

Genetic and Environmental Influences on the Stability of Withdrawn Behavior in Children: A Longitudinal, Multi-informant Twin Study

“…This may be relevant to our analyses, as some studies suggest that parents may be relatively insensitive to the more covert internalizing problems of children (Seiffge-Krenke and Kollmar 1998;Ollendick and King 1994). A previous longitudinal multiple rater study in our sample found that rater disagreement variance accounted for 35% of the individual differences in internalizing problems (Bartels et al 2007a).…”

“…Unlike the WB syndrome scale of the CBCL, the broad band internalizing scale that it is part of, has received a fair amount of attention in the field of behavior genetics. Longitudinal studies in our Dutch twin sample suggested increasing influence of the shared environment and decreasing genetic effects between the age of 3 and 12 years (Van der Valk et al 2003a;Bartels et al 2004bBartels et al , 2007a. Exploring the relative influence of genes and environment on behavioral stability, Bartels et al (2004b) found that both genes (average influence 43%) and shared environment (average influence 47%) had a major impact on the continuity of internalizing problems over time.…”

“…To examine the stability of WB throughout childhood, the psychometric model was extended to incorporate data on all four time points (see Bartels et al (2007a) for a comprehensive description of the longitudinal application of the psychometric model). To gain insight in what factors are important for the continuity of WB, all possible genetic and environmental influences were specified using Cholesky decompositions for both the common and rater specific phenotype.…”

Factors Influencing Female Caregivers' Appraisals of Their Preschoolers' Behaviors

“…These authors argue that studies that focus on the correlation between the parents ratings or between parent and teacher ratings may be missing major discrepancies as the correlation only relates how closely the patterns match not the level or severity of the problems being reported by the informants (Treutler & Epkins, 2003). In a longitudinal study on the internalizing behaviors of twins in the Netherlands, rater disagreement was found to be substantial and the authors stated that rater bias may be persistent over several months to years and can significantly affect the results of longitudinal studies (Bartels, Boomsma, Hudziak, Beijsterveldt, & van den Oord, 2007).…”

Heritability of Testis Size

“…However, this may led to correlated measurement errors which are reflected in the C component in the genetic modelling (Bartels et al, 2007b). Such a form of rater bias could explain part of the estimated common environmental influences on testis size.…”