There are few pleasures as pure, simple and primal as cradling a newborn baby and having it look up into your eyes – this fact has been known and indeed documented for centuries, but until recently it had never been explained scientifically.
Research published in the journal Frontiers in Psychology changed this by looking at the phenomenon of the newborn smell and seeking to explain it in biological and evolutionary terms.
The researchers found that the scent of a baby is in fact a chemically perfect perfume that has evolved to foster the mother-child bonding process – just as babies instantly recognise the scent of their mothers, so too do mothers recognise the smell of their babies, right from the smell of their downy heads all the way to the pungent odour of a full nappy.
The study had 30 women participants, half of whom were new mothers, with the other half not having any children at all. All had their brains monitored by MRI as they were asked to smell various items, including those that were infused with the smell of a newborn.
Although the majority were unable to identify the scent of a newborn, all registered the newborn smell as pleasant. What is more interesting, however, is that the brains of the participants all responded in a particular way to the newborn smell: the dopamine pathways leading to the brain’s reward systems were activated.
What is curious about this reward system activation is that it involved exactly the same processes involved in activities such as eating delicious foods, enjoying good sex or even the taking of recreational drugs. In terms of the mother-child relationship this means that the brain is rewarded for the intimacy inherent in the giving of love and care to a newborn child.
Furthermore, although all the women involved in the study reacted in a similar way, those who were already mothers had a more marked response than non-mothers.
However, the scientists were unable to explain whether the heightened response of mothers was attributable to their changed hormonal state or to the experience of interacting with and smelling their own offspring.
“It is possible that childbirth causes hormonal changes that alter the reward circuit in the caudate nucleus, but it is also possible that experience plays a role,” said one of the researchers.
It is not yet known whether the brains of fathers are activated in the same way, although it is likely that the next few years and further scientific research will provide the answer to this question.