People can quickly and completely switch moral views without realizing it, researchers say after conducting an experiment that tricked volunteers into arguing against their previously stated opinions.

"Many participants had a sense of self-discovery, that they actually were perfectly capable of entertaining and arguing for the issues in a different manner than they originally had expressed," said researcher Lars Hall, a cognitive scientist at Lund University in Sweden.

Hall and other scientists had 160 volunteers fill out a two-page questionnaire about moral issues. This survey asked the volunteers how much they agreed or disagreed with ethical positions such as, "It is more important for a society to promote the welfare of the citizens than to protect their personal integrity," and how the volunteers felt about current hot topics such as whether the violence Israel used in the conflict with the Palestinian group Hamas was morally defensible despite civilian Palestinian casualties.

The researchers then carried out a bit of sleight-of-hand. Each questionnaire came on a clipboard, and completing it required flipping over the first page of questions. The back of the clipboard had a bit of glue, so the flipped-over sheet stuck to it. When volunteers tried flipping that page back over to discuss their answers, a different sheet was revealed instead, containing opposite versions of two of the original questions. (What the volunteers put down remained unchanged.)

For instance, volunteers might have been asked to rate on a 9-point scale how much they agreed or disagreed with the statement, "Large-scale governmental surveillance of email and Internet traffic ought to be forbidden as a means to combat international crime and terrorism." The altered statement now read, "Large-scale governmental surveillance of email and Internet traffic ought to be permitted as a means to combat international crime and terrorism."

If the volunteers had originally replied that they strongly disagreed with government surveillance of email, the altered questionnaires suggested the volunteers strongly agreed with it. [ 10 Historically Significant Political Protests ]

As the participants read and discussed their ratings with the researchers, most of them remained blind to the switch — 69 percent of the volunteers failed to detect at least one of the two changed questions. And many volunteers endorsed the revised opinions, even though those views were the exact opposite to what they had originally declared.

Often the volunteers developed coherent and unwavering arguments supporting these switched views.

"I want to emphasize that our goal was not to try to fool people or to expose flaws in their opinions," Hall told LiveScience. "Depending on the standard you set for how strong attitudes people ought to have for the issues in our study, one might of course lament that many of our participants were not engaged or knowledgeable enough to detect the switches, particularly if you are a policymaker or activist or otherwise involved in the issues yourself. But this is not primarily our view."

The findings suggest people might be more flexible and open-minded in their moral attitudes than they realize, Hall said.

These findings also suggest that polls, surveys and other questionnaires capture only what people say and not what they really do or the entirety of how they feel.

"I think the most important implication of our findings is that it challenges the very conception of what an attitude amounts to and how you can measure it," Hall said.

The scientists detailed their findings online today (Sept. 19) in the journal PLoS ONE.

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