Every year brings another round of news stories about people who become lost in parks. How quickly they are found often depends upon how much wandering around they do while trying to get "found." Do such people really walk in circles? Some just-released research offers a possible answer.
Scientists in the Multisensory Perception and Action Group at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, have published a study in the journal Current Biology.
According to a news release from the Institute:
It is a common theme in many books and films: when people get lost in a desert or a jungle, they end up walking in circles. No matter how hard they try, at some point they will cross their own tracks and despair, because they realize that they will never make it back to civilization.
Surprisingly enough, the belief that people walk in circles when lost is mainly based on anecdotal evidence and has never been studied systematically in a real desert or forest.
Scientists ... led by Jan Souman and Marc Ernst, have now presented the first empirical evidence that people really walk in circles when they do not have reliable cues to their walking direction.
Their study ...examined the walking trajectories of people who walked for several hours in the Sahara desert (Tunisia) and in the Bienwald forest area (Germany). The scientists used the global positioning system (GPS) to record these trajectories.
The results showed that participants were only able to keep a straight path when the sun or moon was visible. However, as soon as the sun disappeared behind some clouds, people started to walk in circles without even noticing it.
The study team dismissed one explanation offered in the past for walking in circles: that most people have one leg longer or stronger than the other, resulting in "a systematic bias in one direction." Dr. Jan Souman said,
"To test this explanation, we instructed people to walk straight while blindfolded, thus removing the effects of vision. Most of the participants in the study walked in circles, sometimes in extremely small ones (diameter less than 20 m).”
However, it turned out that these circles were rarely in a systematic direction. Instead, the same person sometimes veered to the left, sometimes to the right. Walking in circles is therefore not caused by differences in leg length or strength, but more likely the result of increasing uncertainty about where straight ahead is.
Dr. Marc Ernst, Group Leader at the MPI for Biological Cybernetics, added: “The results from these experiments show that even though people may be convinced that they are walking in a straight line, their perception is not always reliable."
Search and rescue personnel have long advised people who realize they are lost in remote areas to stop, find a nearby spot where they will be as safe, comfortable and as visible as possible, and then wait for rescuers to find them. This strategy limits the size of the potential search area and reduces risks to the victim.
Although the research cited in this story indicates study participants stayed on course better if they could see the sun or moon, there was one important detail: they weren't actually lost. If you're lost, you aren't certain which direction you should go, even if you could stay "on course," so just stay put.
An important key for any trip into the boonies: be sure a responsible person back in "civilization" knows your plans, so he can report you overdue promptly if you don't return as expected. Your "safety net" contact needs as many details as possible; information that you're going hiking "somewhere in Yellowstone" is better than no information...but not much!
Two real-world incidents in parks offer some examples that relate to the study's findings.
The newsletter from the Grand County (Utah) Search and Rescue Team includes an interesting comment from one of the team members involved in the search for a missing hiker in Arches National Park several years ago:
I came upon small footprints of a person who was obviously confused or indecisive as the tracks would go a short distance, then double back and go a short distance in another direction...
The hiker was eventually found...but not until she, and the searchers, had done more walking than was really necessary.
A second example confirms that lost hikers can become confused on any continent.
Earlier this year, a 19-year-old tourist from Great Britain got off the trail during a day hike in the Blue Mountains World Heritage Area in New South Wales, a protected area in Australia that includes several national parks. Despite a massive search, he spent nearly two weeks wandering in the rugged terrain.
One major problem: he was a "moving target." Authorities said later that the young man walked in and out of the search area, traveling through areas already covered by searchers. A police commander noted the subject covered a "vast amount of territory," an area believed to be larger than 60 square miles.
In an interview with Britain's Sky News after his rescue, the teenager commented:
"Even when I was off the path, I thought I was only slightly off. I thought I was to the right, if I carry on going left I'll get back on the path....I started circling round and it was when I saw Castle Ruin and Mount Solitary on my left... that's when it really shocked me, that I was in the wrong side of the valley and that I've been walking for a day and half in the wrong direction."
All that wandering certainly made the job of the searchers more difficult, and the young man was fortunate to survive his mishap.
So...if you ever realize you're lost in the woods, desert or similar unfamiliar terrain, don't just do something—stand (or sit) there!
You'll be doing everyone a favor—and you won't find yourself walking in any circles.