Effects of oxytocin on recollections of maternal care and closeness

Abstract

Although the infant-caregiver attachment bond is critical to survival, little is known about the biological mechanisms supporting attachment representations in humans. Oxytocin plays a key role in attachment bond formation and maintenance in animals and thus could be expected to affect attachment representations in humans. To investigate this possibility, we administered 24 IU intranasal oxytocin to healthy male adults in a double-blind, placebo-controlled, crossover designed study and then assessed memories of childhood maternal care and closeness--two features of the attachment bond. We found that the effects of oxytocin were moderated by the attachment representations people possess, with less anxiously attached individuals remembering their mother as more caring and close after oxytocin (vs. placebo) but more anxiously attached individuals remembering their mother as less caring and close after oxytocin (vs. placebo). These data contrast with the popular notion that oxytocin has broad positive effects on social perception and are more consistent with the animal literature, which emphasizes oxytocin's role in encoding social memories and linking those memories to the reward value of the social stimulus.

Fig. 1.

Scatter plot displaying the association between participants’ attachment anxiety score (mean-centered) and change in recollections of maternal care after oxytocin (OXT) [vs. placebo (PL)], with predicted regression line. The dotted curves indicate 95% confidence intervals (CIs). Higher numbers on the care change index (y axis) indicate an increase in care recollections in the oxytocin condition; lower numbers on the care change index indicate a decrease in care recollections in the oxytocin condition; a change score of zero indicates no change in recollections of maternal care across drug conditions. Higher numbers on the attachment anxiety scale (x axis) indicate greater attachment anxiety. Predicted values are shown only for observed levels of attachment anxiety. The predictive equation when other variables are set to their mean value is as follows: change in maternal care = 0.02 – 0.125 (mean-centered attachment anxiety). The effect of attachment anxiety predicting change in maternal care ratings was significant at P < 0.05, two-tailed.

Fig. 2.

Scatter plot displaying the association between participants’ attachment anxiety score (mean-centered) and change in recollections of maternal closeness after oxytocin (OXT) [vs. placebo (PL)], with predicted regression line. The dotted curves indicate 95% confidence intervals (CIs). Higher numbers on the closeness change index (y axis) indicate an increase in closeness recollections in the oxytocin condition; lower numbers on the closeness change index indicate a decrease in closeness recollections in the oxytocin condition; a change score of zero indicates no change in recollections of maternal closeness across drug conditions. Higher numbers on the attachment anxiety scale (x axis) indicate greater attachment anxiety. Predicted values are shown only for observed levels of attachment anxiety. The predictive equation when other variables are set to their mean value is as follows: change in maternal closeness = −0.03 − 0.446 (mean-centered attachment anxiety). The effect of attachment anxiety predicting change in maternal closeness ratings was significant at P < 0.05, two-tailed.