In an era of concern over “fake news,” a new study finds that people draw a distinction between information sources that are dishonest and those that are biased.

Researchers found that a source seen as biased may lose credibility with people, even if they believe the source is scrupulously honest.

That means untruthful – or “fake” – news isn’t the only issue for consumers.

“If you want to be seen as a credible source, you have to be objective, as well as honest and knowledgeable,” said Laura Wallace, lead author of the study and postdoctoral researcher in psychology at The Ohio State University.

The findings are significant because most research has suggested that source credibility is a combination of trustworthiness and expertise, Wallace said. Bias had not been considered, or was viewed as part of trustworthiness.

“I use the example of grandparents,” Wallace said.

“Most everyone agrees that grandparents are honest. But if Grandma says that her grandson Johnny is the best soccer player around, most people will smile politely but not believe her. She’s obviously biased.”

Wallace conducted the research with Duane Wegener and Richard Petty, both professors of psychology at Ohio State. The study was published online today (July 8, 2019) in the journal Personality and Social Psychology Bulletin.

The researchers conducted several related experiments.

In one study, 169 undergraduate students read a fictitious conversation between aid workers trying to decide how to allocate resources at the beginning of an Ebola outbreak in the Congo. They had to decide whether to allocate limited resources to Rutu, a rural area where the outbreak started, or Poko, a nearby city where the disease had spread.

The aid workers were all described as “highly trained.” One worker, Roger, advocated for sending aid to Rutu and for some participants was described as having worked in that area as a Peace Corps volunteer, which might indicate that he is biased. For other participants, this information was omitted, leaving no indication of bias.

After reading the conversation, participants completed a questionnaire in which they evaluated the aid workers’ proposals.

Results showed that when Roger was described as having a previous connection to Rutu, participants thought Roger was biased in his recommendation to send aid to Rutu, – even though they also thought he was trustworthy, an expert in the field, and likable.

As a result, study participants thought his suggestion to send aid to Rutu was less credible, but only when they were told he had previously worked there.

“The guys in this scenario are all trying their best to contain this Ebola outbreak, they all know what they’re doing, and they are all seen as very honest,” Wallace said.

“But people believe that Roger’s experience in one of these regions is affecting his judgment and that he just can’t see things objectively.”

This result shows that bias may damage credibility, just as untrustworthiness does. But that doesn’t mean that bias and untrustworthiness always have the same consequences.

“In the case of biased, but honest sources, the information they present might only support one side of the issue, but at least people can treat the information as useful for understanding that side,” Wallace said.

“Untrustworthy sources may never be that useful.”

In addition, the difference between a biased source and an untrustworthy source has a big impact if the source changes positions. In a separate study that has not yet been published, the same researchers found that when untrustworthy sources change their position, it does not make them any more or less persuasive.

“Untrustworthy sources are seen as unpredictable. You can’t tell what position they are going to take and it is not seen as meaning anything if they flip-flop,” she said.

But the study found that it was quite surprising when biased sources changed their positions on an issue. This surprise had a positive effect on persuasion.

“People believe there must be new evidence that is really compelling to get a biased source to change positions and take the opposite side,” Wallace said.

“So there are sometimes differences in how effective biased sources are compared to untrustworthy ones.”

Wallace noted that the researchers used novel topics in the studies so that participants couldn’t have pre-existing beliefs about them. As a result, the study can’t say how people with their own biases would react to sources with similar or opposing biases.

But, she said, previous studies suggest that people tend to believe that those who agree with them are less biased than those who disagree with them.