Half a century ago, a young Stanford professor named Mark Granovetter published what would become one of the seminal papers in the field of sociology. “The Strength of Weak Ties” argued for the important of mere acquaintances — not just your friends — in the growing field of social network analysis. (It’s been cited more than 73,000 times.)

Granovetter surveyed a few hundred people in the Boston area who had recently taken a new job they learned about through a contact. (It’s who you know, right?) It turned out their weak ties — people they reported seeing once a year or less — were responsible for nearly twice as many job discoveries as their closest friends (people they saw twice a week or more).

In many cases, the contact was someone only marginally included in the current network of contacts, such as an old college friend or a former workmate or employer, with whom sporadic contact had been maintained. Usually such ties had not even been very strong when first forged.

For work-related ties, respondents almost invariably said that they never saw the person in a non-work context. Chance meetings or mutual friends operated to reactivate such ties. It is remarkable that people receive crucial information from individuals whose very existence they have forgotten.

Granovetter’s insight has been fundamental to the explosion of social networking platforms. Facebook is fundamentally a tool for flattening out all your strongest and weakest ties — from your spouse or sibling all the way to that kid you sat next to for two weeks in fifth grade. They all exist side by side, first-class citizens in your feed. LinkedIn was essentially Granovetter’s research turned into a startup. (Indeed, the strongest empirical support for Granovetter’s thesis is a massive study looking at more than 20 million LinkedIn users.)

So why do your weak links matter so much? One big reason is that they’re more likely than your closest friends to possess novel, salient information that you might lack. Your BFFs likely live in roughly the same knowledge universe that you do and are thus less likely to come across a new insight that’s unknown to you. That kid from fifth grade lives far enough outside your personal bubble to present you with a truly important piece of information.

How does that apply to news? Before the internet, news was mostly a strong-tie game. You learned about public events from the local daily paper or TV anchors you’ve watched for years. News that spread by word-of-mouth was mostly transmitted through that smallish group of people you talked with at home, work, or elsewhere. Online, though, a headline might reach you from a news site you’ve never heard of, filtered through the lens of some rando you don’t recognize but who got retweeted by someone you kinda know.

How does the strength (or weakness) of your connection to someone impact how much you believe the things they say online? That’s the question asked by an interesting new paper titled “The Strength of Weak Ties and Fake News Believability.” It’s in the journal Decision Support Systems and its authors are Babajide Osatuyi of Penn State and Alan R. Dennis of Indiana University. From the abstract (emphases mine):

Are we more likely to believe a social media news story shared by someone with whom we have a strong or weak tie? We tend to trust close ties more than weak ties, but weak ties are sources of new information more often than strong ones.

We conducted an online experiment to examine the effect of tie strength (strong ties vs. weak ties) on the decision to believe or not believe fake news stories. Participants perceived false stories from weak ties to be more believable than false stories from strong ties (after controlling for the trustworthiness of the sharer)…

The impact of weak ties does not stem from the novelty of their information, as we used identical headlines across both study groups. Thus, while the strength of weak ties effect is present in this context, the underlying theoretical mechanism differs from the novelty of information traditionally observed in other settings.

This is interesting! Not only are your weak ties more likely to present you with novel or surprising information — you’re also more likely to believe it than you’d be if the same info came from your bestie.¹

Osatuyi and Dennis conducted an experiment with 250 participants — a mix of college students and an online Mechanical Turk sample. Each was asked to identify individuals with whom they had strong or weak ties (after the concept was explained to them). They were then shown Facebook posts showing four different headlines — two true, two false — and presented as shared by either their weak or strong tie. Finally, they were asked to evaluate the truthfulness of the posts on three closely aligned 1-to-7 scales — how truthful, credible, and believable they were.

The results? Subjects “were significantly more likely to believe false stories shared by weak ties.”

Participants were also asked questions meant to evaluate the people they named as their strong/weak ties — namely, on their levels of integrity (example: “I would characterize _____ as honest”), benevolence (“I believe that _____ would share information that is in my best interest”), and ability (“_____ is competent and effective in providing reliable information”).

On each of those variables, subjects rated their strong ties higher than their weak ones — that is, they considered their closer friend to be more honest, benevolent, and able than their less-close one. Even so, they still were more likely to believe their weak tie’s falsehoods than their strong tie’s. And those factors didn’t always interact predictably:

…the reason why social media users are more likely to believe false stories from weak ties is due to the differences in importance between ability and integrity. The perceived ability of the sharer to share reliable information (i.e., detect fake news) matters for both strong and weak ties, but is especially important to the belief of a false story shared by a weak tie.

…In contrast, the perceived integrity of the weak tie matters to the belief of both true and false stories shared by them, but integrity has no effect on the belief of stories shared by strong ties. This finding aligns with [our hypothesis] that ethical reasoning amplifies the impact of integrity on belief in information from weak ties. This highlights the importance of trustworthiness factors and ethical behavior in information sharing on social media…

The positive and significant main effect of the sharer’s ability on belief suggests that perceived ability generally increases belief in information, regardless of tie strength or truthfulness of the information (i.e., true or false).

In other words, a sharer’s “ability” — roughly, “that dude seems to know what he’s talking about” — is always important but most important when it’s a weak tie spewing nonsense. But a sharer’s “integrity” — roughly, “I trust that dude to be truthful and honest” — only matters when it comes to weak ties, not strong ones. (“Benevolence” didn’t matter much for any subgroup.)

…our findings indicate that we believe weak ties more than strong ties (after controlling for trustworthiness) and this may explain the spread of fake news because there are more weak ties than strong ties on social media.

This means that people are more likely to believe false information they learn from the weak ties on social media than the information provided to them by their strong ties. In other words, it may be difficult for close ties (e.g., family members and close friends) to dissuade users from ideas and information they receive from relative strangers (weak ties) they meet and start following on social media…

Finally, this research may have implications for research on how to mitigate fake news. Many interventions to reduce the spread of fake news have taken a rational approach focused on facts that are best assessed using objective, instrumental reasoning. Yet, these interventions have been shown to have little to no effect on belief in fake news…

Past attempts to reduce the spread of fake news have focused on the story (e.g., by flagging fake news) or the source of the story (e.g., by rating sources). Our research shows that who shares a story significantly influences its belief. Since the sharer matters, it may be possible to mitigate fake news by nudging users to pay attention to the sharers of stories.

First, the role that weak ties play in convincing users on social media means that weak ties can become persuading agents for users on social media, which can be helpful for marketing and campaign efforts. Second, to curb fake news consumption and its dissemination, we expand on the recommendation from recent research that calls for healthy skepticism by encouraging users to carefully evaluate information from weak ties. Perhaps more so than strong ties.

1. Squint and you can also see the entire influencer economy in that sentence. [↩]