Earlier this week, three-year-old Joshua Childers wandered away from his home in southeast Missouri wearing only a T-shirt, sneakers and a pull-up diaper. More than 52 agonizing hours later, the 35-pound toddler was found alive three miles from his home in the rugged terrain of the Mark Twain National Forest.

"I went on a hike," the boy said after the ordeal. Then he asked for a glass of milk.

Some are calling Joshua's survival a miracle. Without doubt, it's a story with a very happy ending. It's also a tale that reveals the fascinating science of "lost person behavior" -- who gets lost and who has the greatest chance of survival. And it presents an opportunity to revisit the most important survival rule if you get lost in the woods (or anywhere else for that matter).

Expert trackers say that an average person leaves behind two thousand clues for every mile he travels. Each step you take produces evidence -- a footprint, a broken twig, a clump of mud, a twisted blade of grass. A team of well-trained searchers spaced ten feet apart usually can detect 95 percent of the useful clues. If they're spaced fifty feet apart, they'll discover 75 percent of the clues.

Ken Hill is the world's foremost authority on what's known as "lost person behavior." Hill is a psychologist at St. Mary's University in Halifax, Nova Scotia, a densely wooded place once known as the "lost person capital of the world."

Hill says all you need to know about lost people is their age and their outdoor activity and you can calculate how far they're likely to travel and where you should go looking. You don't need a detailed personal history or psychological profile. You just need some basic information. "It is more important to realize that a known percentage of all lost persons is found within a one- or two-mile radius than it is to know how they got there," he writes.

Hill has interviewed countless people who have gone missing in the woods. He's looked into their wide eyes and listened to the trembling in their voices. "Fear is the enemy," he says. "Fear activates the large muscles in the legs." Lost people want to run. They also lose their heads and sometimes forget even to look in their own backpacks for food and water.

It turns out that no matter where you are in the world, lost people behave in the same way. Who you are determines how far you're likely to wander.

Hunters: In Hill's research, hunters get lost the most often. Typically, when they're found, they've traveled between 0.94 and 2.25 miles. Hunters are usually in pretty good physical condition, but when they're lost, they often push beyond their abilities. Yet they're also easy to find in a search. They're good communicators and they typically have solid outdoor skills.

Hikers: Hikers are another big group that gets lost. They're very dependent on trails and most often don't have maps or compasses. When they're found, they've typically traveled between 0.87 and 2.88 miles.

Small Children: Kids between ages one and six usually travel between 0.67 and 1.65 miles. The smallest ones between one and three, like Joshua Childers, have no idea they're lost. If they're separated from their parents, they have no ability to find their way; they wander aimlessly, and they typically don't go very far. They're usually found sleeping.

Naturally, three- to six-year-olds are more mobile, and they understand the idea of getting lost. They tend to take care of themselves better than older children and even adults. They burrow in bad weather by sleeping in caves or hollows. Typically, they're "stranger resistant," meaning they won't respond to searchers.

Older children between ages seven and twelve will run when they're lost. The distance is usually between 0.92 and 1.70 miles. They're often afraid of punishment, and they won't answer searchers until they're cold and hungry. They have the same fears as adults, only more acute.

The Elderly: Of all the different groups, it turns out older people are excellent survivors because they tend to build shelters and await rescue.

So what should you do if you get lost on a hike? Hill's number one survival tip is to stay where you are or find an open place nearby. Of the eight hundred Nova Scotia lost person reports that he reviewed, only two intentionally stayed in one place in order for searchers to find them more easily. "We always find clues before we find the victim," he says. "What does that tell you?" Hill's point is that if the victims had stayed in one place, they would probably have been found sooner.

For more information about lost person behavior or surviving other kinds of life-changing challenges, please go to The Survivors Club Website.