Let kids be kids — that's some of the most common parenting advice you'll hear. But when it comes to letting them be kids outdoors, many parents take pause. According to one U.K. study, in fact, most kids spend less time outside than incarcerated adults. What a loss.

Every other summer when I was growing up, my family visited my great-grandmother's ranch in the hills of northern California. A bounty of interesting and abandoned structures stood decrepit on this once bustling cattle farm, and it was all mine to discover.

I still remember searching for barn owls in the rafters of the old hay barn and relishing in the capture of the pudgiest bullfrog tadpoles from the dredger ponds. For what seemed like hours, I'd kneel on muddy knees as I earnestly tried to lure feral kittens out from under the front stoop of the farmhouse. Traveling through the fields alone, I was aware of the risk of startling rattlesnakes as I walked through thigh-high wildflowers, or the chance of meeting of an aggressive Angus bull. And the incessant buzz of wasps and hornets was never far away. Yet I was having the time of my life.

It was this faint whiff of danger that cemented my appreciation of nature and ultimately resulted in my choosing conservation education as my profession. Teetering on the edge of risk around the dangers of the ranch increased my attention to the world around me and elevated my respect for animals.

Yet now, as a mother of a 7-year-old son, I ask myself if I'd allow my child to explore nature unsupervised, as I did. Sure, I'm all for family hikes, vegetable gardens and making bird feeders. But my defenses start to rise when I think of my son leaving for hours on end for autumnal rambles through the forest behind our townhouse in Pikesville.

What's changed?

Perhaps it's the fact that we don't know the people who live nearby. Only 20 percent of Americans report spending time with their neighbors, and almost a third have no interaction at all with folks in their neighborhood. When I grew up in the 1970s, it was the reverse: 30 percent of families reported hanging out with their neighbors at least twice a week.

Maybe the kids have less free time? In some cases, yes. However, with the increase in the percentage of two-parent households that have both parents working full-time (46 percent today, compared to 31 percent in 1970), you might expect to see more unsupervised children climbing trees, playing tag and exploring creeks in the late afternoons. Instead, they're holed up inside, according to a study of 12,000 parents in 10 countries: A third of their children spent less than 30 minutes outside per day, and half spent less than an hour each day. In the last 30 years, the amount of children's unstructured outdoor play time has declined by 50 percent.

Finally, there's the media. Widespread coverage of child abductions and other crimes against kids almost certainly feeds into parents' fears — including mine. Although heinous acts against children are committed by people the child knows more than 75 percent of the time, one study reports that 96 percent of newspaper articles focus on ways to protect children from attacks by strangers, which have steadily decreased since the 1970s.

From climate change to endangered species, today's kids will inherit a world wracked by ecological crises. But how can they learn to care about the world if they've never gotten to explore it?

I'll be different, I say. I'll let my son venture into the woods alone to make forts, find salamanders under rocks, leap across ravines and move independently through the forest. I'll say yes to this because I know it will make him a better steward of the planet and more patient, respectful observer of nature. I will do it.

I hope.

Heather Doggett (HDoggett@aqua.org), a New Economy Maryland fellow at the Institute for Policy Studies, directs visitor programs at the National Aquarium in Baltimore.