Directionally Challenged

Unlike, say, the L-shaped bed sheet, a lost person walking in a circle isn’t just for TV or the movies. It’s what happens in real life, says a German study.

Psychologist Jan Souman of Germany's Max Planck Institute for Biological Cybernetics hypothesized that lost people kept left or right. So he set out to test his theory, never imagining that people actually walked in circles, like the Hollywood cliche.

For his study, he roped nine volunteers into agreeing to attempt to walk as straight as possible in one direction for several hours. Wearing GPS receivers (so researchers could analyze their paths), six walkers set off through southern German forests while three braved southern Tunisia’s Sahara desert. (A sandstorm put an end to the Sahara part of the test, reports Discovery News.)

What they found: If there are no cues from the sun or moon, people can’t figure out where they’re going. The four forest walkers who walked through stormy conditions and the desert walker who walked after the moon set all walked in circles. The four other walkers — who could see the sun or the moon — traveled in something approximating a straight line.

"Just walking in a straight line seems like such a simple and natural thing to do, but if you think about it, it's quite [a] complicated thing going on in the brain," Souman told Discovery News. His study was published in the journal Current Biology this week.

In a follow-up experiment — to test whether people walk in circles simply because one leg is stronger than another — Souman blindfolded 15 volunteers and asked them to walk straight. Instead, the walkers made tiny circles (a diameter of less than 66 feet.) Souman repeated the experiment multiple times and each time the walkers ended up making circles in different directions.

Randy Gallistel, a cognitive neuroscientist at Rutgers University in New Jersey, wasn’t shocked by the results. Most dead hikers, he pointed out to Discovery News, are found within a mile of where they disappeared.

Bottom line: Make like a Boy Scout and be prepared, advises Gallistel. Bring a map or compass or GPS device — and at least learn a little about nature before you hit the road. Moss grows on the north side of trees, he told Discovery News. The south facing side of the valley is barer than the north-facing side. And as you learned in elementary school, the sun rises in the east and sets in the west.

"If you are going to move, make sure you know how to move in a straight line," Gallistel told Discovery News, "Straight lines are helpful. Circles don't get you anywhere."

Illustration courtesy of Seamus McGill, via Commons Wikimedia