Several authors have reported that mothers had a leftward bias when holding their newborns. This holding bias was attributed successively to heart beat and to handedness but both hypotheses were rejected. Recent studies in student populations showed that a right hemispheric specialisation in the recognition of facial expressions is linked to this bias, but these results were not observed in a small sample of mothers. Other investigators demonstrated that people suffering from depression or anxiety could present a dysfunction of the right cerebral hemisphere. We have carried out two studies and found that mothers with depressive or affective symptoms hold their newborns on the right side.
Now our objectives are to verify this result in a larger sample of mothers (approximately 300) met in three maternity hospitals after pregnancy. This study aimed at exploring whether affective symptoms (depression, anxiety) or other factors (hemispheric lateralisation, holding position) were related to biases expressed by mothers when they held their newborns.
The statistics analysis is in process, but our hypothesis is that affective symptom mothers hold their newborns on the right side and we want to observe if brain lateralisation has an effect on the holding side bias.
In addition to these fundamental aspects, this research has some practical consequences. Depressive or anxious mothers generally hold their newborns on the right side. Staff concerned with early childhood could thus easily identify these mothers, and be more attentive and if necessary propose a psychological follow-up.