Current child development research invariably points to the interaction between genetic and environmental influences on children.

Understanding the discrete roles played by one or the other is an additional, very difficult step, but, until it can be reliably taken, arguments referring unhelpfully to “some combination of both requiring further research” will crop up far too often in study conclusions.

Collaborations between development specialists and geneticists are an obvious way forward. One example, involving several European universities, has lately been trying to establish how environmental and genetic factors conspire in forming disorganized attachments between infants and caregivers.

The team headed by Gottfried Spangler at the University of Erlangen-Nuremburg has been reconsidering the relationship between maternal responsiveness and attachment security.

Research from a genetic perspective indicates an association with a variation in the serotonin transporter gene. From the developmental perspective, responsiveness is an important factor in the attachment between children and parents.

Spangler and his colleagues hypothesized that serotonin “polymorphs” and maternal responsiveness work in a GxE interaction in the formation of disorganized attachment.

They studied 106 parent child relationships. The quality of the children’s attachment was assessed using the “strange situation” method in which trained observers mark it as “secure”, “insecure-avoidant”, “insecure-resistant” or “disorganized”.

The quality of maternal behavior was assessed by analyzing recordings of play sessions, which examined infants’ signals and the promptness and appropriateness of the maternal response to them.

Reflecting previous findings, the investigation confirmed a connection between the genetic variation and significantly higher incidence of disorganized attachment – but, in line with thinking about the influence of GxE interaction, it did not account for all of the variation in the sample.

The more useful finding was of a coincidence between children who were rated as displaying behavior associated with disorganized attachment and those experiencing low levels of maternal responsiveness and possessing the negative genetic variable.

This interplay between nature and nurture suggests that high maternal responsiveness is a protective factor against the genetic risk of disorganized attachment. Similarly, possession of the more positive genetic variable will protect against the maternal risk.

That said, the authors warn against relying on these conclusions and highlight several studies that have generated contrary findings.

They nevertheless recommend that parents of children with a genetically based vulnerability for disorganized attachment should be offered parental training to increase their responsiveness.

See: Spangler G, Johann M, Ronai Z and Zimmermann P (2009) “Genetic and environmental influence on attachment disorganization”, Journal of Child Psychology and Psychiatry, 50(8) pp 952-961.

• For more about attachment, from the perspective of the eminent UK child psychiatrist Sir Michael Rutter, see: Attachment theory – time science got over it?

• For more about genetics and serotonin, see How gene research is entering the child protection arena, Who's wearing the dopamine receptor genes in your house? and For nature versus nurture the war is over