Malevolent foreign governments, morals-challenged party hacks, and click-hungry opportunists produce fake news, but their misleading posts wouldn't do any damage if no one actually shared them. And when you go looking for who spreads divisive nonsense on Facebook, you find a culprit much close to home.

When a team of researchers out of New York and Princeton Universities dug into the data recently in an effort to get a handle on just who spreads fake news, their investigation led them straight to... your grandfather.

OK, not necessarily your specific grandfather. He might be a politically and technologically savvy guy. But the detailed analysis of the posting histories of 1,300 Americans from the period around the 2016 election did reveal that older folks are nearly four times as likely to share fake news as Millennials.

Who's to blame for spreading fake news? Mostly Boomers.

The good news from the study, recently published in Sciences Advances, is that sharing fake news is actually less common than you might imagine given the media firestorm around the issue. "According to our data, fewer than 1 in 10, or 8.5 percent, of our respondents shared links from fake news domains," report the researchers behind the study, Andy Guess, Jonathan Nagler and Joshua Tucker, in the Washington Post. (Hat tip to Business Insider).

That small amount of sharing wasn't equally distributed among the population, however. One group did wildly more to spread fake news than any other.

"More than 1 in 10, or 11.3 percent, of people over age 65 shared links from a fake news site, while only 3 percent of those age 18 to 29 did so," report the authors. "No other demographic characteristic we examined -- gender, income, education -- had any consistent relationship with the likelihood of sharing fake news."

If you've ever been bombarded by nonsense posts from that one crazy uncle or older acquaintance this might not come as a huge shock to you, but it did surprise Guess, who told The Verge: "For me, what is pretty striking is that the relationship holds even when you control for party affiliation or ideology. The fact that it's independent of these other traits is pretty surprising to me. It's not just being driven by older people being more conservative."

Which isn't to say that conservatives and liberals were equally likely to share fake news. Older folks of either political persuasion were more likely to spread misinformation than their younger counterparts, but conservative seniors spread by far the most.

"While 18 percent of Republicans in our sample shared links from fake news sites, only 3.5 percent of Democrats did," the authors report (self-identified independents shared as much as Republicans). But the authors note that most of the fake news produced before the election was pro-Trump, so conservatives may just have had more options to be misled (or mislead).

Whatever the explanation for conservative older folks being the most prone to sharing misinformation, share they did. "Republicans over the age of 65 were seven times more likely to share fake news than respondents of any political leaning aged between 18 and 29," NewScientist's write-up of the study highlights.

Fixing the problem

These numbers pretty conclusively prove that Boomers are the main culprits when it comes to spreading fake news, so clearly the next question to ask is, why? Does an aging brain tend to make it harder to tell the difference between a genuine news story and a hoax? Or is the main problem digital literacy? Perhaps less technologically experienced seniors just aren't as good at reading the clues that help people tell dubious from dependable sources online.

This research didn't weigh in on that question, but the scientists behind it hope to study the issue further this year with the aim of devising more effective strategies to beat back fake news.