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It is absolutely true. It happened to me once.

I was walking with my son in the Lake District to Crinkle Crags; and, although 
the weather was beautiful with sunshine and scattered 4/8 cumulus to start, 
it deteriorated somewhat and we walked into cloud level/ misty on the top. 
Having got to the top, we turned back to follow the same track to where we 
started. 

Walking back, my son went confidentaly on ahead with what is a relatively 
poorly marked and  uncertain path up on the top of Crinkle Crags,  with the 
broken rock and grassy terrain.  I passed a small pool of water sitting in a 
dip, and walking on, found I was walking on unfamiliar ground instead of the 
barely visible track. I persisted for a while (straight ahead) then was 
absolutely astonished to find after about ten minutes I had, instead of 
walking as I thought in a sraight line back the way I had come, had walked in 
a complete circle - as I was amazed to find I approached the same pool from 
the other direction. It was very wierd I can tell you. I was absolutely 
convinced I was walking in the correct direction.  I got the compass out and 
carried on perfectly correctly and soon caught up with my son on the 'right' 
path.  I had not used the compass as I was utterly convinced I could walk 
back in a sufficiently straight line on what was after all a path of sorts..  
Not so!

This is a well known phenomenon on mountainous territory as one unconscously 
walks along a contour line, which if you are already at the top as I was, 
takes you in a small (or big) circle.

It also known that on flat level ground everyone walks with a slight bias in 
step length on one side - thus you walk in a circle.

The only way to stop it, is to fix direction with sticks in the ground for 
reference as back-bearings; or, to look ahead and fixate on a feature in the 
distance. (Or use a compass!).

In the 1950s (or was it 60s - can't remember)  the Antartic expeditions using 
caterpillar tracked vehicles to get to the Sotuh Pole used a mirror set-up in 
the driver's vision of the front vehicle, to enable him to look backwards so 
the driver could look back along his track made in the snow, and thus keep a 
straight line ahead.  It was very effective apparently as he was making a 
continuous back-bearing on his own tracks with which he could see immediately 
if he veered off track.

Douglas Denny.
Chichester. England.
======================

Original message:

"Common belief has it that people who get lost in unfamiliar terrain often end 
up walking in circles. Although uncorroborated by empirical data, this belief 
has widely permeated popular culture. Here, we tested the ability of humans 
to walk on a straight course through unfamiliar terrain in two different 
environments: a large forest area and the Sahara desert. Walking trajectories 
of several hours were captured via global positioning system, showing that 
participants repeatedly walked in circles when they could not see the sun. 
Conversely, when the sun was visible, participants sometimes veered from a 
straight course but did not walk in circles. We tested various explanations 
for this walking behavior by assessing the ability of people to maintain a 
fixed course while blindfolded. Under these conditions, participants walked 
in often surprisingly small circles (diameter < 20 m), though rarely in a 
systematic direction. These results rule out a general explanation in terms 
of biomechanical asymmetries or other general biases [1], [2], [3], [4], [5] 
and [6]. Instead, they suggest that veering from a straight course is the 
result of accumulating noise in the sensorimotor system, which, without an 
external directional reference to recalibrate the subjective straight ahead, 
may cause people to walk in circles."
 
From the current issue of 'Current Biology':
http://www.cell.com/current-biology/home



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