Genetic and environmental influences on ratings of manifest anxiety by parents and children

Parental reports and children's self-reports of manifest anxiety were obtai ned from a community-based sample of twin pairs on two occasions approximat ely 19 months apart, using the Revised Child Manifest Anxiety Scale (Reynol ds & Richmond, 1978). Tn prior cross-sectional studies, a low degree of agr eement between parent and child assessments of anxiety was found. Furthermo re, parental reports were found to reflect a higher heritability than child ren's self-reports (Eaves ct al., 1997; Thapar & McGuffin, 1995). The index of temporal stability was moderate for all informants (circa r =.5 to r =. 6). To test whether the components contributing to the temporal stability d iffered between the informants, structural equation models were fitted to t he data using the program, Mr: Statistical Modeling (Neale, 1995). The resu lts showed substantial differences in genetic effects according to both gen der and informant. For children's self-reports, temporal stability was larg ely a function of environmental effects, with ge genetic effects contributi ng a modest 20%, whereas for parental reports, temporal stability was large ly a function of genetic effects. The heritability was higher for parental reports than for boys' self-reports and the genetic covariance between pare nts and their sons was near zero, indicating that they were reporting on qu ite different aspects of anxiety. However, for girls, heritability for mate rnal reports was lower than for self-reports, and the genetic covariance be tween mother and daughter was about the same as that between mothers and fa thers, meaning that they were assessing the same genetically influenced asp ect of anxiety. These results highlight the need to focus on gender differe nces. (C) 1999 Elsevier Science Ltd. All rights reserved.