A recent study led by researchers from UCL has found that babies show higher levels of the hormone oxytocin when their mothers frequently use language to express the child’s thoughts or emotions. Oxytocin, a hormone involved in various psychological functions, plays a significant role in forming social bonds, like those between parents and children, fostering trust, and enhancing social comprehension throughout life.
This study, published in Development and Psychopathology, involved filming 62 new mothers, aged between 23 and 44, interacting naturally with their infants, aged three to nine months, over a five-minute period. The team then assessed the footage to measure how accurately the mother referred to her baby’s inner experiences, such as thoughts, feelings, desires and perceptions. The researchers also collected saliva samples from the infants to measure oxytocin levels.
Upon analyzing the relationship between these two factors, the researchers found a positive correlation. Dr. Kate Lindley Baron-Cohen, the lead author from UCL Psychology & Language Sciences, explained, “We’ve known that oxytocin is involved in intimate social relationships, including the bond between mother and child. We also knew that a mother’s ability to understand her infant’s thoughts and feelings in the first year is a reliable indicator of the child’s future social and emotional development. However, the underlying mechanisms remained unclear.”
She continued, “Our findings reveal a direct correlation between a mother’s discussion of her infant’s thoughts and feelings and the infant’s oxytocin levels for the first time. This suggests that oxytocin plays a role in regulating children’s early social experiences, which are in turn shaped by the parent-infant interaction.”
For instance, when a child shows interest in a toy, a mother who comprehends her child’s inner state might say, “Oh, you like this toy” or “You’re excited”, and may even mimic the child’s actions or facial expressions. The study suggests that this parental mirroring of the child’s experience influences the infant’s oxytocin system.
The study also discovered that mothers suffering from postnatal depression referred to their infant’s internal states less frequently than mothers without depression.
Dr. Lindley Baron-Cohen concluded, “This study unveils a novel psychobiological connection between mothers and their infants, with the mother’s emotionally sensitive speech mirrored in her infant’s hormone levels. This underscores the pivotal role mothers play in their child’s early development and hints at ways to support mothers with depression to aid their child’s social development.”
This research was supported by the National Institute for Health Research (NIRH) ARC North Thames, the Lord Leonard and Lady Estelle Wolfson Foundation, Wellcome Trust, the University of York, the Fund for Psychoanalytic Research through the American Psychoanalytic Association, the International Psychoanalytical Association, the Michael Samuel Charitable Trust, the Denman Charitable Trust, and the Galvani Foundation.
