G x E interaction in the organization of attachment: mothers' responsiveness as a moderator of children's genotypes.
BACKGROUND
Scholars acknowledge that both biologically-founded child temperament and environmental factors are influential in determining the quality of infant-mother attachment. We present evidence for gene by environment (G x E) interaction in the organization of attachment.


METHODS
Participants were 88 typically developing infants and their mothers. Molecular genetic measures of the infants focused on the polymorphism in the serotonin transporter gene (5-HTTLPR, ss/sl vs. ll genotype). Mothers' responsiveness to their infants at 7 months was observed in lengthy naturalistic interactions, and was conceptualized as the environmental influence.


RESULTS
For infants with a short allele (ss/sl ), variation in mothers' responsiveness was significantly associated with attachment security, assessed at 15 months in the Strange Situation. For those infants, low responsiveness predicted particularly high risk for insecure attachment, and high responsiveness offset that risk. For infants homozygous for the long allele (ll ), there was no association between responsiveness and attachment organization.


CONCLUSIONS
The findings show that the quality of early care serves to amplify or offset the risk conferred by genotype.
Barry
Robin A
RA
Department of Psychology, University of Iowa, Iowa City, Iowa 52242, USA. robin-barry@uiowa.edu
Kochanska
Grazyna
G
Philibert
Robert A
RA
D000342:Affective Symptoms / Q000235:genetics* / Q000523:psychology; D000483:Alleles; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D009034:Mother-Child Relations; D009035:Mothers / Q000523:psychology*; D009769:Object Attachment; D011110:Polymorphism, Genetic / Q000235:genetics; D011237:Predictive Value of Tests; D012307:Risk Factors; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D012931:Social Environment; D013694:Temperament
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins