Remember when the Representative from the state of Louisiana, John Fleming, believed that the Onion article about the opening of a Planned Parenthood abortionplex was real? Yes, people all too often believe that articles from satirical newspaper The Onion are true, but more importantly, it was probably the feeling of "truthiness" that appealed to Fleming.

Defined by comedian Stephen Colbert, "truthiness" is the feeling that something is real even when it is not. Interestingly, a group of researchers studied the phenomenon of "truthiness" in Canada and New Zealand and found that people often fell prey to "truthiness" if there was a picture accompanying the false fact – like there was with The Onion's abortionplex article.

Lead investigator Eryn J. Newman, from the Victoria University of Wellington, New Zealand, and her colleagues conducted four different experiments both in Canada and in New Zealand. They would present people with a number of claims like "Giraffes are the only mammal that cannot jump." (The only mammal that cannot jump is the elephant.) When accompanied by a picture that did not even reveal whether the statement was true or not, such as a photo of a giraffe, people were more likely to believe the false claim.

Another experiment, this one split into two parts, showed participants the names of familiar or unfamiliar celebrity names and told to quickly affirm or deny statements of "This famous person is alive" or "This famous person is deceased." When a picture of the celebrity performing an action for which he or she was famous, people were more likely to believe that the statement about the unfamiliar celebrity was true, regardless of whether it was or not.

Previous findings have established that, when people can bring information to mind, it helps make things feel more correct. This study confirms that idea.

The research has implications for situations in which people encounter decorative photos, like in education or in the media because the pictures grab people's attention, it may have unintended consequences.

So when people say that a picture tells a thousand words, it is important to remember that those words may not all be true.

The study was published in the journal Psychonomic Bulletin and Review.