So what exactly is it about infants that bend us to their will? There is no definite answer, but scientists have a few good guesses. "One theory is that it comes from chemicals secreted from a baby’s sweat glands," George Preti, PhD, an analytical chemist at the Monell Chemical Senses Center, told Women's Health magazine. According to Dr. Preti, that smell only lasts about six weeks, because babies' metabolism changes as they begin eating and drinking on their own instead of getting their nourishment through the umbilical cord.
Another theory, says Dr. Preti, is that the smell comes from the vernix caseosa, which is the whitish cheese-like substance that coats a newborn’s skin just after he enters the world. It’s typically washed off, but the scent may continue to linger on the baby’s hair and skin.
As this and other research shows, scent is a pretty powerful force, and one that seems to have a direct pathway to our brains. Scent has been shown to trigger memories, protect us against harmful toxins (such as when we smell food that’s rotten) and bind us to things we love, like a romantic partner or a baby. And it seems to be something even infants can do. Previous research has shown that babies show preference for clothes that have been worn by their own mothers and are calmed by the scent of their own mother’s milk (but not that of other mothers) when they’re in pain and distress, which is one reason why hospitals commonly place an article of mom’s clothing inside a pre-term baby’s incubator. A 2001 study has also shown that infants are more likely to reach for pads that have been soaked with their own mom’s breast odor. A 2006 study even found that moms didn’t mind the smell of their own baby’s poop as much compared to that of other babies. Now that’s love.
Although the newborn scent will eventually fade, moms will tell you that they’ll continue to love the smell of their own kids. Many parents report loving the smell of their babies long into toddlerhood and beyond. And while it probably won’t last into days when your big kid comes home sweaty and gross after playing in the dirt with his friends, the memory of the baby smell isn’t likely to fade.
BY Katherine Lee, What to Expect