A Dirty Kid is a Happy Kid! Why Everyone Should Play in the Dirt

Evelyn returns from preschool, clothes covered in dirt; from her grandmas house stained from head to toe; from an outing with a friend, hands so dirty she could write her name with the grime on her fingernails. Apologies ensue. “I’m sorry she got so dirty.” or “I would have washed her if I’d had the time.” or “She sat down right in the dirt before I could stop her.”

And always I reply, “A dirty kid is a happy kid! PLEASE don’t apologize.”

Let kids get dirty and, if you can suppress your vanity for a moment, get dirty with them! Some of the most beneficial bacteria is found right on the bottom of your feet, so go ahead, get some grit and grime between those toes!

Bacteria is NOT the Enemy – So Much For the Hygiene Hypothesis

Bacteria has a bad reputation, as though any and all of it will hurt you. Parents keep immaculate houses in attempt to eliminate the “threat” of bacteria, removing shoes indoors, washing hands with anti-bacterial soap, moping with disinfectants, cleaning the counters with bleach. All of this is not only unnecessary for health but harmful to the immune system. It’s surprising just how many benefits there are to getting (and staying) dirty.

1. Mycobacterium vaccae improves mood
There are all sorts of beneficial bacteria living in the dirt but one that has been well researched is called Mycobacterium vaccae (M. vaccae). This bacteria has been shown to allay depression.

It is not entirely clear why but researchers have found that contact with the bacteria releases cytokines which activate the nerves in our bodies to relay signals to the brain and release serotonin into the prefontal cortex – the part of the brain involved in mood regulation (exercise has been shown to have similar effects).

2. Mycobacterium vaccae is linked to higher IQ
This same release of serotonin that occurs when playing in M. vaccae laced dirt, has also been shown to improve cognitive function. The serotonin that is released whilst playing in the dirt temporarily boosts the IQ so that learning is facilitated.

3. Staphylococci heals wounds
Staphylococci often gets a bad rap but it has it’s benefits as well. Staphylococci can prevent inflammation. After an injury if staphylococci is present on the skin, the redness and swelling which often accompanies cuts and scrapes can be prevented. Forget the ointment, just use a good smearing of dirt before you bandage up!

4. Soil microbes boost the immune system
Playing in the dirt introduces the immune system to bacteria which it can then store in memory. The memory of the immune system is profound and protects a growing body from getting sick later in life. A strong immune system also provides resistance to allergies.

5. Clay improves digestion
Dr. Weston A. Price noted in his book Nutrition and Physical Degeneration (one of my favorite books on earth by the way) that clay was “the treatment used by several primitive races for preventing and correcting serious disturbances in the digestive tract. This consisted in the use of clay or aluminum silicate which modern science has learned has the important quality of being able to adsorb and thus collect toxic substance and other products…” He also noted a common thread running through all of the primitive cultures he studied was that they carried clay in their backpacks. 

Clay isn’t found in every dirt mound but it always seems that kids are magnets to it. It lays deeper in the soil and is fun to play with.

Playing in the Dirt is Good Exercise

No one will dispute that kids need more exercise, and no kid will dispute that playing outside is good fun. Encourage and provide an outdoor space for kids to play and they will. Once they’re out there they will move around quite a bit. Outside is where all the best games of cops and robbers happen, where tag and hide and seek are played. There are trees to climb and frogs to catch. That’s all exercise.

Playing in the Dirt Cultivates a Love for the Outdoors

If you never know something, it’s hard to care about it. Many kids these days never know the outdoors beyond the school playground or their own backyards, if they even have one. Getting kids outside to play (as a place to act out make believe worlds and explore) creates happy memories with the one most primal element in our world: nature.

Playing in the Dirt Shouldn’t End with Childhood

What a better excuse to play with your kids than to head out to the dirt! I personally can’t stand playing with toys (I particularly abhor plastic toys and just don’t find them fun at all). It’s a serious source of guilt for me during the winters actually. In every other way I’m a fine parent, but I just can’t stand getting on the floor to play house and dolls and tea parties.

On the other hand, once summer roles around I can be found any day of the week building sand castles at the river, swinging on the monkey bars, or rolling down a grassy hill. I grew up playing outdoors and I still love it.

Wood Toys (outdoor materials) vs Plastics

When frost and snow cover the dirt, and kids come inside to play, parents have to choose what toys their kids play with.

Back to the topic of bacteria. Let’s be clear on the difference between pathogenic bacteria and beneficial bacteria. There are some bacteria that help us and there are some that hurt us. What can be found in the great outdoors typically doesn’t hurt us. You really don’t need to worry about the kids digging tractor roads in the back yard or climbing trees in the mountains. They won’t get sick from that.

In general worrying about bacteria is counterproductive because exposure to bacteria strengthens the immune system. But I can see how you might not want your kids getting their hands on every cold virus that comes around.

Replacing plastic toys with wooden ones can assuage your paranoia, keep them away from pathogenic bacteria as well as from toxic substances.

The difference between wooden and plastic toys is huge. An article describing the difference in the retention of harmful bacterial in both wooden cutting boards and plastic cutting boards, as well as a study on plastic toys in hospitals reveals how harmful plastic toys can be.

Plastic toys put kids at risk of absorbing dioxins and phthylates from PVBs, and bisphenol-A (BPA), and lead. Wooden toys don’t contain these harmful chemicals (although, you should always be sure your wooden toys are painted with non-toxic paints).

I am a huge fan of Melissa and Doug’s wooden toys. I’ve always tried to buy most of my daughter’s toys wood or cloth and keep her away from hormone altering plastics. I definitely don’t want her starting puberty at 9!

Nevertheless, wooden toys are mostly sterile and don’t provide all the benefits of playing in the dirt… unless, of course, you take the wood toys out to the dirt. When they come back, their porous surface might just hold on to some of the beneficial bacteria they picked up!