"Go ahead," I told the little girl. "Pick up the rock, see what's underneath."

Her chubby, 4-year-old arms struggled with the unwieldy rock buried in the stream bed, likely left behind as detritus from the last ice age. She moved it to one side, keeping one sandaled foot braced against the side of the bank and the other knee-deep in water. Her eyes got big as she examined the damselfly nymphs after their nest was disturbed. She watched quietly, as they wriggled into the water and past her foot. She was too young to know that the larval form of the flying insect was what others might call "gross."

She gently rolled the rock back over the muddy bottom, gazed around at all the rocks in the upstate New York summer stream and said, "Are there nymphies under allllll the rocks?"

This wasn't school, and it wasn't Finland — it was a nature-focused summer camp in New York's Hudson Valley that I ran when I was 17. But hearing about that Nordic country's kindergarten programs, where kids spend up to 80 percent of their time outside, reminded me of my own childhood and that summer program. (We had a large tent to take cover in if need be, but we were outside about 95 percent of the time.) When I turned the kids over to their parents at the end of the day, they were tired, ready for dinner and bursting with new knowledge, inspired by nature. Through that lens we covered language and storytelling, math, history, biology, art and music.

Europe leads the way

Finland's "forest kindergartens" take a similar tack, using the natural world as a jumping off point for early academic instruction. Finland is following in the footsteps of other European countries (including Denmark, featured in the video above), where outdoor education has been common for decades. Here in the U.S., similar ideas are spreading from a program in Vermont throughout New England.

In the Finnish program, 14 5- and 6-year-olds spend four days a week, from 8:30 a.m. to 12:30 p.m., outside with a teacher and two aides. Built into the program is quite a bit of free playtime. Kids get a lot of exercise (instead of being expected to sit quietly at a desk for hours on end) and lesson plans are loosely structured so teachers can use what's at hand and in season in their lessons.

It's time to get outside

While all this sounds less rigorous than a classroom-based kindergarten program, the results show that these types of programs tend to have better results for overall physical health as well as academic performance and social development: "Schools with environmental education programs score higher on standardized tests in math, reading, writing and listening," and "Exposure to environment-based education significantly increases student performance on tests of their critical thinking skills," according to data compiled by the National Wildlife Federation. Kids who play together outside have enhanced social skills. Several studies, including this one from the National Institutes of Health, have shown that learning and playing outside can alleviate ADHD symptoms.

But aren't the kids who do this coming from wealthy, educated communities — so, of course they score better on tests? In fact, some suggest that the greatest gains from spending time outdoors can be found in kids who are coming from less advantageous backgrounds. At a charter school near Atlanta, where kids spend 30 percent of their day outside, students have improved scores more than students any school in their county, and the majority of kids there come from low-income families. "In standardized reading tests, last year’s third-graders outperformed the national average by 17 points and the regional average by 26 points," according to The Atlantic.

The idea that the very youngest of children find it more fun to be outside while learning makes sense from their point of view. Maybe this kind of early outdoors education — along with the rising popularity of forest bathing and the acknowledgment of the physical and mental importance of spending time outside — means that we, as a culture, have reached peak time spent indoors.

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.