It’s a truism among critics of the mainstream media that the greatest power possessed by a journalist is deciding via an intensely subjective process whether a proposed story is “newsworthy.”

A familiar way of understanding the process is recalling that when the proverbial dog bites the man, it’s not news. But let the man turn around and take a bite out of the dog and you’ve definitely got news.

But how important—i.e., newsworthy—is it that the man sank his teeth into the poor hound instead of the other way around? The story could go on the front page above the fold with a huge headline, especially if the biter happens to be an Oklahoma celebrity like Garth Brooks or Baker Mayfield.

A different editor, however, might also choose to put the story out front but instead place it below the fold or perhaps drop it on a page inside the A section.

A third, more skeptical editor would perhaps move the story to the front of the local news section. Or kill it entirely because something more important and unexpected suddenly happens.

Remember, too, that this process works in reverse. A Washington Post editor, for example, put a Nov. 28, 2018, story about Supreme Court Justice Brett Kavanaugh resuming coaching duties with his daughter’s basketball team in the newspaper’s “Public Safety” category.

That placement constituted a not-so-subtle editorial endorsement of the hyper-sensational but wholly unproven allegations about Kavanaugh that nearly derailed his Senate confirmation hearings.

Don’t hold your breath waiting for the Post editor who made that placement decision to come forward with a public explanation for such a transparently political action.

Editors in all forms of news media make such decisions all the time; it’s among the most important things they are paid to do. Less glamorously, they also have to take the calls or answer the emails from angry readers upset because story A got better or worse play than story B.

Such calls and emails tell us that readers also make judgments about which news stories are more or less important than others. But do readers make their decisions differently than the editors and reporters in the newsrooms?

As it is, there isn’t a lot of research on how either readers or journalists make such decisions, but a fascinating new study was recently published that shines much-needed light on the reader side of the question.

The study was done by professors Harold Pashler of the University of California, San Diego, department of psychology, and Gail Heriot of the University of San Diego School of Law.

Pashler and Heriot randomly selected 260 individuals, including 131 men and 129 women, with a mean-average age of 34.8 years, for their initial analysis. A second group of 309 people was held back for analysis after the work with the first group was completed.

Measures were taken of each participant’s position on the political spectrum ranging from liberal to conservative. Then, on a series of six issues, participants were asked to rate the newsworthiness of two hypothetical news stories representing opposing points of view.

As an example, the first issue was government aid to the poor. Hypothetical story one focused on a welfare fraud case, while story two stressed that recipients allegedly received too little assistance to make nutritious meals.

Similarly, divergent hypothetical stories were presented to participants on the other five issues, including affirmative action, military spending, racial bias in law enforcement, gay marriage, and the environment.

Pashler and Heriot began their study with a working theory that “peoples’ views on a given issue will predict differences in their ratings of the two hypothetical news stories associated with that issue.”

“The difference was expected to reflect a bias towards rating as more newsworthy any story that provides partisan ammunition for the rater’s preferred issue position.”

On the surface at least, that’s what they found.

“Overall political ideology is substantially correlated with the tendency to judge as more newsworthy stories providing ‘ammunition’ for the subject’s overall political affiliation,” according to Pashler and Heriot.

But it’s not simply a matter of readers liking or rejecting a particular news story based on whether or not it helps them “win” office debates on current issues like building a wall on the border with Mexico, putting a federal bureaucrat between you and your doctor, or starting a trade war with China.

Looking deeper into their participants’ responses, Pashler and Heriot found that stories getting the highest rating for newsworthiness are those “the rater feels other people ought to pay attention to, items thought likely to compel a neutral party to reach the same opinions as those held by the rater.”

Put another way, if the 260 individuals studied by Pashler and Heriot are representative of news consumers in general, it suggests readers judge newsworthiness by persuasiveness, not partisan utility in office debates or traditional measures long employed by journalism professionals in America’s newsrooms.

To put it bluntly, for most Americans, all facts are not created equal.

But what about the reporters and editors who decide what is news and how it should be presented to consumers?

Pashler and Heriot acknowledge that “it certainly cannot be ruled out that training in a journalism school and/or experience working in an editorial position might permit people to transcend the bias revealed here, with skilled practitioners making purer and more refined newsworthiness judgments.”

Most mainstream media journalists would like Americans to see things with such rose-colored assumptions. Pashler and Heriot don’t seem inclined to buy it. Their concluding observation is this:

These formulaic rules of journalism, while important, do not provide any effective resistance to biases that arise earlier, in the process of deciding which stories are newsworthy enough to deserve coverage in the first place. The current results suggest that biases in this phase might be strong and insidious.

Having spent more than three decades as a reporter and editor working with legions of journalism colleagues in newsrooms serving the nation’s capital, I can assure Pashler and Heriot that “strong and insidious” barely begins to describe the depth of the bias.