Interactional synchrony refers to how a parent’s speech and infant’s behaviour become finely synchronised so that they are in direct response to one another. It was defined by Feldman (2007) as a “temporal coordination of micro-level social behaviour” and as “symbolic exchanges between parent and child”. Synchrony is an important concept relevant to diverse domains in physical, biological and social science. During early development, synchrony involves a matching of behaviour, emotional states, and biological rhythms between parents and infants that together forms a single relational unit. We’ve all seen parents cradling their infants, cooing, smiling, widening their eyes, in a preverbal dance of expression and movement as parent and child each anticipate the other’s response, creating the life-affirming parent-child bond.
In a research led by Lisa Feldman Barrett, a distinguished professor of Psychology at Northeastern University, it has been found that the neurotransmitter ‘dopamine’ is involved in human bonding, bringing the brain’s reward system into our understanding of how we form human attachments. These findings have important implications for therapies addressing postpartum depression as well as disorders of the dopamine system such as Parkinson’s disease, addiction, and social dysfunction. Barrett says,
“The infant brain is very different from the mature adult brain—it is not fully formed. Infants are completely dependent on their caregivers. Whether they get enough to eat, the right kind of nutrients, whether they’re kept warm or cool enough, whether they’re hugged enough and get enough social attention, all these things are important to normal brain development. Our study shows clearly that a biological process in one person’s brain, the mother’s, is linked to behaviour that gives the child the social input that will help wire his or her brain normally. That means parents’ ability to keep their infants cared for leads to optimal brain development, which over the years results in better adult health and greater productivity.”