Lynn Erdman will never forget the first time she gave her oldest daughter a bath. “The eyes got big like, ‘What is this?'” says Erdman, a nurse and CEO of the Association of Women’s Health, Obstetric and Neonatal Nurses. “And the cooing and the laughing and giggling — those types of things that occur make parents turn childlike as well.”

For years, parents have valued bath time as intimate (and adorable) moments with their children. In fact, about 84 percent of parents say it’s some of the best quality time with their children they get, according to a Johnson & Johnson survey of over 3,500 parents worldwide last year. Health professionals, meanwhile, have long understood that regular baths are important to maintain kids’ hygiene. Now, researchers are learning that everyday rituals such baths and diaper changes are critical for babies’ development.

“Scientists are now recognizing [that] everyday interactions parents have with their baby and everyday moments … can be thought of as learning moments or learning opportunities,” says Andrew Meltzoff, a developmental psychologist and co-director of the Institute for Learning & Brain Sciences at the University of Washington. “Previously, we just thought that your baby was fed and slept and would grow independent of the stimulations.”

The Magical First Three Years

By a child’s third birthday, his or her brain is already about 85 percent of an adult’s size. Three-year-olds can move, use language and make moral judgments about what’s fair in the world, Meltzoff says. “Their social-emotional, cognitive development and brain development in the first three years of life is absolutely astounding, and scientists are trying to figure out how the human brain can learn that rapidly and absorb culture that rapidly,” he says.

To better understand it himself, Meltzoff likes to take the baby’s perspective. When it comes to baths, a young brain might find bubbles fascinating because some float up, not down like toys, pacifiers and other objects. Bubbles are also transparent and have surfaces, but aren’t solid. “The baby brain is tuned to pick up patterns and regularities in the world,” and bubbles defy them, Meltzoff says. “You notice that they’re doing little science experiments in the bath tub trying to figure out how the world works.”

Babies also listen to their parents talking, and pick up speech patterns. They notice that your lips go wide when you pronounce the last syllable of “baby,” for example, and that “bubble” and “bath” begin with same sound and matching mouth shape. “[Parents are] the baby’s first and best teachers,” Meltzoff says. “We are teaching, they are learning, and they all happen before school.”

Multi-Sensory Experiences

Bath time is also a time for touch, which is critical for cognitive and emotional development, says Tiffany Field, a developmental psychologist and director of the Touch Research Institute at the University of Miami School of Medicine.

When parents rub their baby’s skin in or out of a bath, it stimulates the vagus nerve, which is linked to different parts of the body. “It slows down the physiology, so it slows heart rate, it slows blood pressure, it changes brain waves in the direction of relaxation,” Field says. “So it’s basically a relaxation kind of response that occurs to having pressure receptors stimulated.”

Field’s research has also linked touch with less aggression among kids. In one of her studies comparing families in Paris to families in Miami, she and colleagues found that Parisian parents use more affectionate touch and also have kids who are less aggressive in school. Other studies of children in orphanages have shown just how dire touch deprivation can be, as it’s even linked to death, Field says.

“Bath time is significant because it’s the time probably that babies get touched more than any other time during their wake time, and so it becomes a very important activity for the parents,” she says.

But it’s not just touch that makes bath time special. It’s also the engagement of other senses, from watching bubbles burst to listening to water splash to smelling soap. “Babies brains are built to really pay attention and really light up when there’s multi-sensory stimulation,” Meltzoff says. In other words, the more senses you can engage, the better.

One of Field’s studies, which was funded by Johnson & Johnson, compared baths with lavender-scented soap to baths with no scent. She and colleagues found that babies in the scented baths cried less and spent more time in deep sleep afterward, and that stress hormone levels of both mothers and their babies declined. “Having an aroma in the bath oil is helpful in terms of making the mother and baby more relaxed,” Field says.

A Technology-Free Time

The hands-on nature of bath time makes it a rare hands-off time for technology, too. Johnson & Johnson’s survey found that 64 percent of parents say they rarely or never use a cellphone during bath time. That’s compared to only 50 percent who don’t use a cellphone while getting their kids ready for bed and 46 percent who don’t use one during “cuddle time.”

David Mays, a pharmacist on Johnson & Johnson’s research and development team, says bath time should be a “technology-free zone.” “You can’t replace a bath with a cell phone or an iPad,” he says. “It’s you and your child, and it’s a perfect time to connect.”

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