Humans are apparently biologically programmed to double back when disoriented, according to researchers in Tübingen. From forests to the deserts, a failure in the sensory-motor system is behind the self-defeating behaviour.
"The stories of people walking in circles when they get lost can in fact be scientifically explained," Dr. Jan Souman of the Max-Planck Institute for Biological Cybernetics said. "Humans don't go in a straight line when they lose sight of reference points, such as buildings, hills, the sun or the moon."
The research group, which also includes scientists from Canada and France, suspect that the tendency originates in a disturbance of the nervous system. When people lose their external pointers, the researchers found that it is very difficult for them to readjust and hold their course to keep them on their journey.
The results come from a study in which scientists left six participants to make their way through a German forest without directions, and a further three hardy test subjects to do the same in the Sahara Desert. The experts tracked the course of these human guinea pigs using GPS navigations systems. Additionally, the scientists blind-folded a further 15 participants, letting them free in an empty field to find their way.
The study's findings, published in the latest issue of Current Biology, showed that the subjects left in the forest and the Sahara could only keep on course so long as they could see either the moon or the sun. As soon as the sun disappeared behind cloud, they lost their orientation and began to walk in circles, all the time unaware that they were taking such a route.
"Inaccurate information builds up in the sensory organs, leading to a circular course," Souman said.
Amongst those blindfolded and observed in the field, most, more or less by chance, departed from the most direct route. The majority of the participants moved in ever smaller circles, with only three of the 15 showing a clear tendency to keep moving in the right direction.
The researchers are now keen to continue research into how people use information to orientate themselves. They are developing a computer program to simulate a landscape in which the scientists hope to study how people direct themselves in a virtual forest. Through this study, they hope to establish which factors are most important to our sense of direction.