Background: The amount of parental investment or attachment to their offspring is an important determinant of offspring success.  Using animal models, a number of groups have demonstrated that these attachment behaviors are strongly influenced by both genetic and epigenetic factors.  In particular, variation in the serotonergic pathway has been strongly implicated.  Unfortunately, studies of these influences in humans using traditional family study designs are strongly biased by residual gene environment correlations.  

Objective:  In order to examine these influences in a less biased fashion, we examined the relationship of offspring serotonin transporter (5HTT) genotype, methylation, and behavioral status on their perceptions of parental assessment using clinical and biological samples from 571 subjects who participated in the Iowa Adoption Studies (IAS). 

Methods: Adoptee genotype and methylation status were determined using standard genotyping and mass spectroscopy techniques, respectfully.  Behavioral status was determined using the Semi Structured Assessment for the Genetics of Alcoholism (SSAGA) interview.  Attachment behavior was assessed using the Parker Parental Bonding Assessment.  Data was analyzed using general linear models. 

Results:   Neither 5HTT genotype nor methylation status was associated with proband assessment of parental warmth or overprotection. The presence of depression, antisocial behavior or substance use in the proband was strongly associated with assessments of parental warmth and overprotection. 

Conclusion:  The assessment of parental competency is strongly correlated with Adoptee behavioral but not genetic status.  Future studies to determine the exact nature of the relationship between perceptions of parental competency and behavioral illness are indicated.