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Tue September 27, 2011
How Psychology Solved A WWII Shipwreck Mystery
Originally published on Mon April 23, 2012 10:52 am
In November 1941, two ships crossed paths off the coast of Australia. One was the German raider HSK Kormoran. The other: an Australian warship called the HMAS Sydney. Guns were fired, the ships were damaged, and both sank to the bottom of the ocean.
The loss of the Sydney in World War II was a national tragedy for the Australians, particularly because none of the 645 men onboard survived. In the years that followed, there was intense interest in finding the wrecks, particularly the wreck of the Sydney. The idea was that doing this might give the families of the lost sailors some measure of peace, a sense of closure and certainty.
The problem was that the only witnesses to the battle and the sinking were about 300 German sailors who had abandoned their ship after it had been hit. They were eventually picked up by the Australian military.
After their capture, most of these Germans were interrogated and asked to identify where the ships had gone down. But the Germans seemed quite fuzzy on this point.
Bob Trotter, a former director of the Finding Sydney Foundation, a nonprofit group established to help find the Sydney, says their ignorance isn't all that surprising.
"Particularly in a wartime situation, the position of the ship is really kept in the bridge area," Trotter says. "It would not be normal that the rest of the ship's company would be told."
Still, in the course of their interrogations, about 70 Germans did come up with a location. But those locations, taken together, didn't make much sense — the positions were spread out, smeared over hundreds of miles. One survivor even placed the sinking almost halfway to Antarctica.
So most Australians concluded that the Germans must be lying, their conflicting accounts part of a ploy to throw the Australians off the scent. When Sydney hunters went out looking for the boat — and many did — they either completely disregarded the accounts from the Germans, or, in a couple of cases, focused exclusively on the captain's version of the story.
Then came psychologists Kim Kirsner and John Dunn.
Kirsner, a cognitive psychologist from the University of Western Australia, first became interested in finding the Sydney in the 1990s. After attempting some different approaches to solving the problem, he brought in his friend and frequent collaborator, a cognitive psychologist at the University of Adelaide.
By the time Dunn entered the picture in the mid- to late 1990s, all kinds of people with all kinds of theories had already attempted to find the ships.
"If you didn't believe the Germans," says Trotter of the Finding Sydney Foundation, "the number of possibilities were endless as to what might have happened and where the ships might be. Lots of theories had been expounded, and lots of areas had been suggested."
The cycle was always the same: Some treasure hunter with a theory would propose a site; people would rush off to look; there would be excitement, then disappointment.
How We Remember Stories
As cognitive psychologists, Kirsner and Dunn took a very different view of the German accounts. To them, the spread of the reports looked like the kind of data they saw in memory experiments. So they set out to prove scientifically that the Germans were probably telling the truth.
"We wanted to make the case — show that the characteristics of these reports were the right kind of characteristics," says Dunn. That is, that the inconsistencies in the reports were precisely the kind of inconsistencies that occur naturally from failures of memory and the vagaries of transmitting information from person to person.
To make this case, Dunn says, they turned to the work of the British psychologist Sir Frederic Bartlett.
Bartlett, like Kirsner and Dunn, was a psychologist interested in what happens to memory over time. In the 1930s he conducted a famous experiment with a Native American folk tale called "The War of the Ghosts."
"The War of the Ghosts" is a very odd tale, at least compared with typical British stories, Dunn says. It has bizarre sentence construction and unpredictable leaps in the narrative.
Bartlett read the story aloud to a test subject, then immediately asked the person to repeat it back. He would transcribe these recall attempts, then, several days or weeks later, go back and have the person repeat what he remembered again. Again, Bartlett would transcribe it. Over a period of months, and in some cases, years, he would return to these people repeatedly and ask them to tell the story — each time transcribing the changes in the narrative.
Here are the first two sentences of "The War of the Ghosts":
One night two young men from Egulac went down to the river to hunt seals, and while they were there it became foggy and calm. Then they heard war cries and thought: "Maybe this is a war party."
And here's how Bartlett's test subject "R" recalled the story immediately after first hearing it:
There were two young men, and they went on the river side. They heard war cries.
Here's how R recalled the same two sentences 14 days later:
There were ghosts. They went on a river.
And the same sentences after a month:
There were ghosts. There took place a fight between them.
Obviously, one expects there to be changes in any repeated narrative, but what Bartlett found was that the changes he saw were, in fact, somewhat predictable.
"In their recall attempts, they try to change the elements of the story in a way that made them make more sense," says Dunn.
Essentially, the British storytellers tried to make the stories conform to a more traditional Western narrative. This made Bartlett theorize that memory is composed of two parts.
When a memory is made, the content you're trying to remember is embedded in a schema, or theory of what is going on. Over time, you remember less of the original content and more of the general theory. That is, you remember the basic gist of the story, and supplement it or change it so that it fits a more comfortable mold. The same pattern of change is seen as a story passes from one person to the next — another experiment that Bartlett did.
Validating The Germans' Stories
So how does this relate to the Germans? Dunn and Kirsner decided that the German survivors' reports should be compared directly with the Bartlett experiment.
To do this, they took the story versions that Bartlett had documented and counted up all of the changes in them. Every time there was a shift in a sentence or a word, they noted it and put that change down on a graph. This produced a particular statistical profile.
Kirsner and Dunn then did the same thing with the German accounts. They arranged the 70 accounts into groups that seemed to be related to one another, then charted them on a graph.
"What we found was that there was a correspondence — that our data looked like the kind of data that Bartlett had generated in his study," Dunn says.
This suggested to Kirsner and Dunn that the Germans were not, in fact, lying.
"It means it's not a contrived set of data," says Kirsner. The variance they saw was the kind of natural variance you get with normal memory loss.
After Kirsner and Dunn determined that the Germans were most likely telling the truth, they sat down together with a map of the Indian Ocean and tried to pinpoint the place on the map that best fit all of the different accounts of where the ships had gone down.
"We took each point in the ocean and looked at how well it satisfied or conformed to each of these statements," Dunn says.
They then marked a spot as the place where they thought the German ship would be found. In 2004, Kirsner and Dunn gave the information to the Finding Sydney Foundation. At that time there were no real plans to go hunting for the ships, so that — at least as far as Dunn was concerned — was that.
"I never really thought that I would ever find out whether it would be right or wrong," he says.
But then a funny thing happened: professional shipwreck hunter David Mearns got interested in finding the Sydney. Mearns and the Finding Sydney Foundation joined forces the Australian government agreed to support an expedition. In March 2008 Mearns went out and discovered the wreck of the German ship.
So how far was the ship from the point that Kirsner and Dunn had marked down four years earlier?
"It was 2.7 nautical miles from the point we put down," Dunn says. "I thought, 'Whoa! It worked!' I was amazed, actually."
A couple of days after the German ship was found, Mearns also found the Sydney. The boat had sunk to the bottom of the ocean only a short distance away from the raider that had attacked it 67 years before.
STEVE INSKEEP, host: It's MORNING EDITION from NPR News. I'm Steve Inskeep.
DAVID GREENE, host: And I'm David Greene in for Renee Montagne.
We're going to hear next the strange tale of how psychology pinpointed the location of a sunken ship. In November of 1941, the middle of the Second World War, two ships crossed paths off the coast of Australia. One was a German raider called the Kormoran, the other, an Australian warship called the Sydney.
Guns were fired, both ships were damaged and both sank to the bottom of the ocean. It was two Australian psychologists working for a nonprofit called the Finding Sydney Foundation who located the wreckage of the boats. NPR's Alix Spiegel explains.
ALIX SPIEGEL: This story begins at the end of a battle, with two ships - both mortally wounded - drifting away from each other in the middle of the night. According to Bob Trotter, who used to direct the Finding Sydney Foundation, 300 of the surviving German sailors had packed themselves into lifeboats and were sitting there in the darkness watching the ship that they had just attacked slowly disappear.
BOB TROTTER: All they saw of Sydney was a glow on the horizon, which in the words of the German captain suddenly went out - no explosion, nothing, just a glow that suddenly went out like a light being switched off. And that was the last anyone saw of Sydney for 66 years. And all of the 645 men on board.
SPIEGEL: Now apparently this loss of the Sydney was really devastating for the Australian public.
TROTTER: The nation was thunderstruck. Sydney was what I guess you could describe as she was the jewel in the Navy's crown.
SPIEGEL: And then she wasn't. Then she was a pile of steel at the bottom of the Indian Ocean. But where, exactly was that pile? That was the question put to the 300 surviving Germans. Unfortunately, most of those Germans were fuzzy on where precisely the ships went down, which, Trotter says, isn't all that surprising.
TROTTER: Particularly in a wartime situation where the position of the ship is really kept in the bridge area, it would not be normal that the rest of the ship's company would be told.
SPIEGEL: Still, when the Germans were picked up and interrogated, around 70 did come up with a location. It's just those locations didn't make a lot of sense.
KIM KIRSNER: The positions are spread out, smeared over hundreds of miles.
SPIEGEL: This is Kim Kirsner, one of the two psychologists who worked on finding the Sydney. And he says the locations were all over the map, literally.
KIRSNER: A hundred and twenty miles from the coast. There's another one just 160 miles from Cape Cuvier. There's another one which is 130 miles from Shark Bay, which is a different type of referent.
SPIEGEL: One survivor placed the sinking halfway to Antarctica, which understandably raised this question in the minds of the Australian people.
JOHN DUNNE: There was a lot of discussion about whether you could believe these reports.
SPIEGEL: That's John Dunne, the second psychologist who worked to find the ships.
DUNNE: People were saying you can't believe what they are saying because these are the enemy. They're going to be telling lies under interrogation. And the reason you're getting all these different reports is that they're all telling different kinds of lies.
SPIEGEL: And according to Bob Trotter, because there was so little faith in the German reports, wild theories about what had happened and where the boats might be flourished.
TROTTER: If you didn't believe the Germans, the number of possibilities were endless as to what might've happened and where the ship might be.
SPIEGEL: But as cognitive psychologists, Kirsner and Dunne took a very different view of the German accounts. To them, the spread of the reports looked like the kind of data that they saw in memory experiments. And so they set out to prove scientifically that the Germans were probably telling the truth. John Dunne:
DUNNE: Show that the characteristics of these reports had the right kind of characteristics that you'd expect to see if it was all due to failures of memory and to the vagaries of transmitting information from person to person.
SPIEGEL: Now to make this case, Dunne says, they turned to the work of a British psychologist.
DUNNE: Sir Frederic Bartlett.
SPIEGEL: Sir Frederic Bartlett, like Kirsner and Dunne, was a psychologist interested in what happens to memory over time. And in the 1930s he did a series of experiments with a Native American folktale called "The War of the Ghosts." Now this story was, at least to a British mind, very, very strange, with lots of bizarre leaps in the narrative.
DUNNE: So the story starts by saying, there were two young men from Egulac.
UNIDENTIFIED WOMAN: One night, two young men from Egulac went down to the river to hunt seals, and while they were there it became foggy and calm.
SPIEGEL: So in one of these experiments Bartlett would tell somebody this story.
DUNNE: Then he'd ask them to tell the story back to him. And he would write that down. He would then wait a little while, go back to those people and ask them to tell the story a second time.
SPIEGEL: Then he would write that down. And over months and years, he'd come back to that same person again and again and document how the story changed each time. So for example, listen to how one person changed the first two sentences of the story. Here's version one:
UNIDENTIFIED WOMAN: (Reading) There were two young men. They went to the riverside. They heard war cries.
SPIEGEL: Version two, 14 days later:
UNIDENTIFIED WOMAN: (Reading) There were two ghosts. They went on a river.
SPIEGEL: Version three, after a month:
UNIDENTIFIED WOMAN: (Reading) There were ghosts. There took place a fight between them.
SPIEGEL: So you see there's change. But the way Bartlett saw, it the change happens in very predictable ways.
DUNNE: In their recall attempts they try to move the elements of the story in a way, or change them in a way, or add things to them so that made them make more sense.
SPIEGEL: That is, they tried to make the stories conform to a more traditional Western narrative. And this made Bartlett theorize that memory is composed really of two parts. When you make a memory there's this content that you're trying to remember, which you embed in a schema or general theory of what is going on. And over time you remember less of the original content and more just the general theory. So you're remembering the basic gist of the story and supplementing it or changing it so that it fits a more comfortable mold.
You see the same pattern of change if you pass the story from one person to the next, which is another experiment that Bartlett did.
So how does all of this relate to the Germans?
DUNNE: We thought, OK. All of these reports by the survivors can be thought of rather like this experiment by Bartlett.
SPIEGEL: So what Dunne and Kirsner did was that they took the story versions from Bartlett and counted up all of the changes in them. So every time there was a change in a sentence they noted it and they put that on a graph.
DUNNE: We can count up the different kinds of versions of these stories and that has a particular statistical profile.
SPIEGEL: Then they did the same thing with the German accounts. They arranged the 70 accounts into groups that seemed to be related to one another, and then they charted them on a graph.
DUNNE: And what we found was that there was a correspondence, that our data looked like the kind of data that Bartlett had generated in his study.
SPIEGEL: If you placed one graph over the other, their profiles matched, which suggested to them that the Germans were not in fact lying.
KIRSNER: It means it's not a contrived set of data.
SPIEGEL: So after all this, Kirsner and Dunne sit down with a map of the Indian Ocean, and what they did was try to pinpoint the place on that map which best fit all of the different accounts of where the ships had gone down.
DUNNE: That's what we did: we just took each point in the ocean, and we looked at how well it satisfied or conformed to each of these statements.
SPIEGEL: They then marked that spot down as the place where they thought the German ship would be found. And in 2004, gave that information to the Finding Sydney Foundation. Now, at that time there were no real plans to go hunting for the boats. So at least as far as John Dunne was concerned, that was that.
DUNNE: I never really thought that I would ever find out, you know, that if it was going to be right or wrong.
SPIEGEL: But then a funny thing happened. A professional shipwreck hunter named David Mearns independently convinced the Australian government to let him go searching for the wrecks. In March of 2008, he went out and actually discovered the wreck of the German ship. So how far exactly was the ship from the point that Kirsner and Dunne had marked down four years before?
DUNNE: Two point seven nautical miles from where it was found.
SPIEGEL: Two point seven nautical miles.
DUNNE: I thought, whoa...
(SOUNDBITE OF LAUGHTER)
DUNNE: ...it worked. I was amazed actually.
SPIEGEL: A couple days after the German ship was found, the wreck hunter David Mearns also found the Sydney. The boat had sunk to the bottom of the ocean a short distance away from the ship that had attacked it 67 years before.
Alix Spiegel, NPR News, Washington. Transcript provided by NPR, Copyright NPR.