The students were also asked how clearly they remembered the prank, and the first grade story was at least equivalent to, and in some times greater, than their memory of the true events.
"This indicates that these subjects false memories were as compelling as memories of the true events," the researchers wrote in their report.
But does that mean we are all just sitting ducks for false memories of things that never happened?
Not really, Lindsay says.
He points out that there were some "quite potent suggestive influences" that undoubtedly helped shape the students memories.
"We had told the students that their parents said these things happened to them, so the authority of the parent" comes into play, he says. Plus, the first two stories were true, so students who remembered them had no real reason to doubt the third. And Hagen played an aggressive role, cajoling the students and urging them to rev up their memories.
"So it's not like people are developing false memories at the drop of a hat, or in response to one or two suggestive questions," Lindsay says. "There's quite a lot of suggestive influence piled up here."
Of course, some prosecutors digging into possible child abuse cases also have been known to be "suggestive" when interviewing children, but Lindsay says that's a different ball park.
It's one thing to convince someone they remember a relatively harmless childhood prank, and quite another to dredge up memories of traumatic events.
"The likelihood of one kind of false memories doesn't necessarily predict the likelihood of another," he says. Recalling previous research, he adds:"We know that a single passing suggestion can be enough to get two-thirds of a group of undergraduates to report that they saw something in a film that they didn't see. But that's not very rich, and elaborate, and personal or meaningful.
"It takes a lot more to get people to have a false memory of pulling a prank, and it would take far more to get people to believe they had been abducted by aliens, or raped by their parents," Lindsay says.
So it takes a much more aggressive approach to implant false memories of a terrible, personal trauma. By the way, at the end of the research project the students were all told that one of the three events was false, and they were asked to guess which one it was. All but three said they thought it was the story about the first grade prank, the "pseudoevent," as the researchers put it.
But they were astonished to realize that an event some of them recalled so clearly had never happened. "You mean that didn't happen to me?" one of them asked.
"If you didn't tell me it was a false event, I would have left here thinking I did this," said another. "No way," said yet another. "I remember it. That is so weird."
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.