People are significantly more likely to believe that a product or medication is effective when a scientific-looking graph is presented with product claims, even when the graph presents no additional information, a new study has found.

Advertisers and psychologists have long known that medical imagery such as brain scans and X-rays or scientific jargon can be used to add credibility to product pitches. Such images and technical-sounding ingredient names — such as 10 billion lactobacillus casei bacteria — create a halo of credibility that trades on the persuasive nature and trustworthiness of science.

People assign higher credibility to medical images that are impossible for them to accurately interpret or understand, but they also appear to be persuaded when the image is as simple as two bars of differing heights on a graph, said co-author Aner Tal of Cornell University.

“When people are presented with something that appears to be based on objective data or scientific evidence it makes product claims more convincing,” said Tal.

The researchers made the graphs as simple as possible to ensure that the mystique of science could not play a role in people’s judgments.

Study participants were shown a brief passage of text outlining the effectiveness of an immune-boosting product. Half the group was also shown a simple graph with one bar roughly twice as tall as the other.

People were asked how effective the medication was on a nine-point scale based on the information provided and also whether the medication would reduce the incidence of illness.

More than 96 per cent of the group that saw the text with the graphic believed the medication could reduce illness, compared with 67 per cent of those who saw the text alone. The bar graph also increased the effectiveness people assigned the medication.

In a second round of testing, the researchers found that a stronger belief in science as a “conveyor of truth” was associated with stronger persuasiveness of graphs that were pointless and redundant.

“Companies know that they can make their claims more convincing with images people won’t understand, but we also showed the effect when the image is so simple that everyone can understand it,” Tal said.

Graphs and chemical formulas appear to signal a scientific basis for product claims and that a general belief in science increases the credibility of those visuals, the authors say.

“Science to some degree has replaced religious sources of truth, so it gets a lot of credence as an arbiter of truth and that can be abused,” he said.

Product claims often contain references to clinical trials or other scientific analysis without any detail on the method or the results.

“They are really just saying ‘We have done some science-y stuff so to show that this is a good thing,’” said Tal. “People really need to take a good look at the evidence before using a product that could affect their health.”

The article, Blinded With Science, was published in the journal Public Understanding of Science.

rshore@vancouversun.com

Blog: vancouversun.com/greenman

Twitter:@theGreenManblog

Click here to report a typo or visit vancouversun.com/typo.

Is there more to this story? We'd like to hear from you about this or any other stories you think we should know about. CLICK HERE or go to vancouversun.com/moretothestory