My wife and I often find ourselves on opposite ends of a parenting spectrum—the cleanliness spectrum, to be exact. Just the other day, our toddler dropped a cracker on the kitchen floor. Before I could say, “Five-second rule,” she swooped in with a disinfectant wipe, the cracker swiftly disposed of. “She’ll be fine,” I said. “A little dirt builds character.” My wife wasn’t convinced. For her, it’s all about sanitized play areas, spotless hands, and avoiding every germ lurking in grocery store shopping carts. For me? Let her go barefoot in the backyard and lick a popsicle that fell on the deck. Who’s right? Honestly, I’m not sure.

This disagreement got me thinking about the broader debate: Is it better to keep your child clean and sanitized, or should we let them get a little dirty to build immunity? Let’s dive into the pros and cons of each side, along with what science has to say.

The Case for Cleanliness

It’s no secret that good hygiene is essential for keeping illnesses at bay. According to the Centers for Disease Control and Prevention (CDC), regular handwashing is one of the most effective ways to prevent the spread of infectious diseases like the flu and COVID-19. Clean environments also reduce exposure to harmful bacteria and viruses that young children—with their still-developing immune systems—may struggle to fight off.

For parents, cleanliness offers peace of mind. Sanitizing toys, wiping down surfaces, and using hand sanitizer before meals create a controlled environment that feels safe. It’s especially critical for families with medically fragile children or those with compromised immune systems. In these cases, a sanitized space isn’t just a preference; it’s a necessity.

Pros of Cleanliness:

• Reduces the risk of infections and illnesses
• Prevents the spread of contagious diseases.
• Creates a controlled, safe environment for children.

But is there such a thing as being too clean?

The Case for Dirt and Germs

On the flip side, exposing children to everyday germs can be crucial for building a robust immune system. Studies suggest that early exposure to microbes—found in dirt, on animals, or even in less-than-spotless environments—can help train the immune system to distinguish between harmful and harmless substances. Without this exposure, the immune system may overreact to benign triggers, potentially contributing to the rise in allergies and autoimmune diseases.

A Finnish study published in Science Advances found that children who were exposed to forest soil showed improved gut microbiota and immune function compared to those in urban environments (source). This supports the “hygiene hypothesis,” which suggests that overly sanitized environments may hinder immune system development.

Additionally, allowing children to explore the world—barefoot in the grass or hands deep in the sandbox—fosters curiosity and a sense of adventure. Sure, they’ll get dirty, but those experiences can shape their understanding of the world.

Pros of Germ Exposure:

• Helps develop a stronger immune system.
• May reduce the risk of allergies and autoimmune diseases.
• Encourages exploration and sensory learning.

The Evidence on Over-Sanitization and Allergies

The rise in allergies and autoimmune diseases in industrialized nations has been linked to increased sanitation. According to a review in The Journal of Allergy and Clinical Immunology, children in highly sanitized environments are more likely to develop conditions like asthma, eczema, and food allergies (source). The study highlights that children who grow up on farms or in households with pets—both rich in microbial diversity—tend to have fewer allergies.

Another factor is the delayed introduction of certain foods. Research has shown that introducing potential allergens, such as peanuts, earlier in a child’s life can actually decrease the risk of developing an allergy. Over-sanitization, it seems, is doing our kids no favors.

Striking the Right Balance

So, what’s the answer? Like most things in parenting, balance is key. Proper hygiene practices—like washing hands after using the bathroom or before eating—are non-negotiable. But there’s no need to sanitize every surface your child touches or prevent them from experiencing the natural world.

Think of the immune system like a muscle. If you don’t use it, it becomes weak and ineffective. Just as lifting weights strengthens your body, encountering germs strengthens your immune system. Over-sanitizing might feel like protection, but it could leave the immune system undertrained and unprepared for real threats.

Conclusion: Embrace the Dirt, Within Reason

In today’s over-sanitized world, it’s important to remember that a little dirt won’t hurt. Let your child run barefoot in the grass, play in the mud, and yes, even eat that cracker they dropped on the floor (most of the time). These experiences not only build immunity but also foster resilience and curiosity.

At the same time, teach your children good hygiene habits that protect them from genuine risks. Wash hands after playing outside or before meals, but don’t stress about sterilizing every inch of your home.

After all, life is messy—and that’s okay.