Conflict of interest statement: No conflicts declared.
Genetic and environmental influence on attachment disorganization
Article first published online: 13 FEB 2009
© 2009 The Authors. Journal compilation © 2009 Association for Child and Adolescent Mental Health
Journal of Child Psychology and Psychiatry
Volume 50, Issue 8, pages 952–961, August 2009
How to Cite
Spangler, G., Johann, M., Ronai, Z. and Zimmermann, P. (2009), Genetic and environmental influence on attachment disorganization. Journal of Child Psychology and Psychiatry, 50: 952–961. doi: 10.1111/j.1469-7610.2008.02054.x
- Issue published online: 16 JUL 2009
- Article first published online: 13 FEB 2009
- Manuscript accepted 26 September 2008
- gene–environment interaction;
Background: Empirical studies demonstrate that maternal sensitivity is associated with attachment security in infancy, while maternal frightening/frightened behavior is related to attachment disorganization. However, attachment disorganization is also predicted by individual dispositions in infancy. Indeed, recent studies indicate a link between attachment disorganization and DRD4 gene polymorphisms, thus suggesting a genetic vulnerability for attachment disorganization. The aims of our study were twofold, to test a) a possible direct link between molecular genetic variations and attachment disorganization, and b) a possible gene–environment interaction with a moderating effect of early maternal caregiving.
Methods: Attachment security and disorganization, as well as quality of maternal behavior were assessed in the infants of the Regensburg Longitudinal Study IV (N = 106) at the age of 12 months. DNA samples were collected in order to assess the exon III repeat polymorphism in the coding region and the −521 C/T single nucleotide polymorphism (SNP) in the regulatory region of the DRD4 gene and a repeat polymorphism (5-HTTLPR) in the promoter region of the serotonin transporter gene.
Results: Significant associations were found between attachment disorganization and the short polymorphism of the serotonin transporter gene. Also, a gene–environment interaction indicated that this genetic association was only valid for infants of mothers exhibiting low responsiveness. No other significant genetic associations with attachment disorganization were apparent.
Conclusions: The study suggests a gene–environment interaction whereby biological determinants of attachment disorganization are moderated by social experiences. Different pathways of the development of attachment disorganization are discussed based on a bio-behavioral model of development.