At first this condition might seem more the domain of helpful aliens and guardian angels than doppelgängers, but third man syndrome falls smack in the middle of our rogue’s gallery of mysterious doubles.
You’ve probably heard these stories before. A mysterious stranger seemingly appears out of nowhere to help someone through extreme circumstances — and then vanishes.
Mountaineer Frank Smythe shared part of his climb through Everest’s low-oxygen “death zone” with just such a phantom stranger and Sir Ernest Shackleton famously enjoyed similar company on his Imperial Trans-Antarctic Expedition. In the case of Antarctic explorer Peter Hillary, the presence manifested as the double of his dead mother.
Sometimes the stranger literally provides a helping hand, other times they just inspire a positive, encouraging vibe. As Michael Shermer points out in this Scientific American article, however, four scientific explanations really push all the ghosts, aliens, angels and spirits off the suspect list:
1. Isolation triggers the mind to hallucinate the normal feeling we get when we’re working or traveling among other people.
2. The rational cortical control over emotions shuts down due to oxygen deprivation, sleep deprivation or exhaustion. This opens the door for inner voices and imaginary companions (similar to some cases of alien abduction experiences).
3. Out temporal lobe body schema (the brain’s image of our body and what it’s doing) is tricked into thinking you have a double. Ever up for a game of rationalization and story making, the brain then constructs a plausible explanation for this double’s presence.
4. The mind schema, our psychological sense of self, is simply coordinating independent neural networks to solve the problem of survival in an extreme situation. The hallucination comes out of its function of making us feel like we’re a single mind.
By and large, it seems that this breed of doppelgänger is nothing to fear. Rather, if you happen to encounter one, you probably have far, far more pressing concerns in your life. So just enjoy the company and try not to freeze to death. Here’s an interview with “The Third Man Factor” author by John Geiger:
About the author: Robert Lamb is a senior writer and podcaster at HowStuffWorks, where he co-hosts Stuff to Blow Your Mind with Julie Douglas. He has a love for monsters, an aversion to slugs and a hankering for electronic music.