Mental representations of attachment in identical female twins with and without conduct problems.

Insecure mental representations of attachment, a nearly invariant feature of cluster B personality disorders, have never previously been studied in twins. We conducted the Adult Attachment Interview (AAI) on 33 pairs of monozygotic (MZ) female twins reared together as an initial exploration of causal influences on mental representations of attachment. As predicted by attachment theory, we observed substantial twin-twin concordance for attachment security (odds ratio 13.8; P = 0.001), a similar level of concordance between twins and their non-twin siblings, and an inverse relationship between attachment security and current level of aggression (P = 0.01). These data indicate that there are minimal effects of non-shared environmental influences (or measurement error) on attachment classifications derived from the AAI. In this sample of twins with and without histories of Conduct Disorder, mental representations of attachment appear to be highly familial, i.e., strongly influenced by either shared environmental factors, genetic factors, or both.

Validation of a brief quantitative measure of autistic traits: comparison of the social responsiveness scale with the autism diagnostic interview-revised.

Studies of the broader autism phenotype, and of subtle changes in autism symptoms over time, have been compromised by a lack of established quantitative assessment tools. The Social Responsiveness Scale (SRS-formerly known as the Social Reciprocity Scale) is a new instrument that can be completed by parents and/or teachers in 15-20 minutes. We compared the SRS with the Autism Diagnostic Interview-Revised (ADI-R) in 61 child psychiatric patients. Correlations between SRS scores and ADI-R algorithm scores for DSM-IV criterion sets were on the order of 0.7. SRS scores were unrelated to I.Q. and exhibited inter-rater reliability on the order of 0.8. The SRS is a valid quantitative measure of autistic traits, feasible for use in clinical settings and for large-scale research studies of autism spectrum conditions.