Michelle: Everything you think you know about fake news might be wrong. The common story is that we're all just one click away from being duped. But what if the real problem isn't that we're too gullible, but that we're too stubborn? Mark: Hold on, what? My entire social media feed is a museum of people falling for the most obvious nonsense. I see it every day. How can we not be gullible? It feels like our defining feature right now. Michelle: That is exactly the question the cognitive scientist Hugo Mercier tackles in his fascinating 2020 book, Not Born Yesterday: The Science of Who We Trust and What We Believe. He makes the provocative case that our brain's default setting isn't gullibility, but a very sophisticated, and very ancient, kind of skepticism. Mark: I love that title. Not Born Yesterday. It’s so punchy. It’s basically saying, “I’m not an idiot.” But making that claim in today's world, with all the talk of misinformation, feels incredibly bold. Michelle: It is. And his argument is a journey. To understand it, we first have to confront all the evidence that seems to prove him wrong. We have to look at why we're so convinced that we, as a species, are total suckers.

Mark: Okay, I'm ready. Where do we start? Because I have a long list of examples. Pizzagate, flat-earthers, my cousin who thinks crystals will align his chakras... Michelle: Let's go bigger. Let's go to 19th-century South Africa, to the Xhosa people. They were facing a devastating crisis: a lung disease, likely introduced by European cattle, was wiping out their herds, which were central to their entire way of life. Mark: A terrible situation. They must have been desperate. Michelle: Utterly. And into this desperation steps a young prophetess named Nongqawuse. She comes forward with a vision. She says the spirits of their ancestors told her that if the Xhosa kill all their remaining cattle and destroy their crops, the ancestors will rise from the dead, drive the British into the sea, and replenish the land with healthy cattle and grain. Mark: Oh no. I can see where this is going. That sounds like a recipe for disaster. Michelle: It was a catastrophe. Hundreds of thousands of cattle were slaughtered. Widespread famine followed, and tens of thousands of people died. It's a heartbreaking story, and on the surface, it looks like a textbook case of mass gullibility. A whole society destroyed by one person's prophecy. Mark: Exactly! How do you argue with that? It seems to prove the point that under the right emotional pressure, people will believe anything. Michelle: Mercier would say we need to look closer at the context. The Xhosa weren't just blindly following a strange command; they were already in an apocalyptic situation. Their world was collapsing. The prophecy, as radical as it was, offered a powerful, all-encompassing solution that fit within their spiritual framework. It was a desperate gamble in a situation with no other good options. Mark: That’s a more charitable reading. It wasn't just random foolishness; it was a response to total desperation. But what about more controlled settings? I'm thinking of those classic psychology experiments. Michelle: You mean like the Milgram obedience experiments? Mark: Right, the shock experiments! Where ordinary people, just following orders from a guy in a lab coat, were willing to administer what they thought were lethal electric shocks to another person. That seems to be pure, unthinking deference to authority. Michelle: It's one of the most chilling studies in psychology, for sure. But Mercier points out a few details that complicate the "we're all just sheep" narrative. The power of the experiment depended heavily on its setting. When it was conducted at a prestigious university like Yale, with the experimenter in a crisp lab coat, obedience was high—around two-thirds of participants went all the way. Mark: Okay, that's the scary number we all know. Michelle: But when Milgram’s team replicated the experiment in a run-down office building in a nearby town, with no affiliation to a famous university, obedience dropped dramatically. Less than half went to the end. Mark: Huh. So it wasn't just a guy in a coat. It was a guy in a coat backed by the perceived authority and credibility of a major scientific institution. The cues mattered. Michelle: The cues were everything! People weren't just obeying an order; they were deferring to what they perceived as legitimate, trustworthy science. They were using clues from their environment to decide if the authority was credible. And that subtle difference is the key to Mercier's entire argument.

Mark: Okay, so if we're not just mindless followers, what are we? What's the alternative? Michelle: The alternative is that we are what Mercier calls "discerning omnivores" of information. We have to take in information from others to survive, but we can't just swallow everything. So, we've evolved a mental toolkit he names 'open vigilance.' Mark: Open vigilance. It sounds like a cybersecurity software for your brain. How does it work? Michelle: It's this constant, mostly unconscious, balancing act. We're open to new information, but we're also vigilant against being misled. To make it clear, Mercier uses some incredible examples from the animal world. Take the Thomson's gazelle. When it spots a predator like a wild dog, it doesn't always just run. Sometimes, it does this bizarre thing called 'stotting.' It leaps straight up into the air, over and over, with its legs held stiff. Mark: That sounds like the worst possible thing to do. Why would you waste energy and show off to something that wants to eat you? Michelle: Because it's a signal. It's a very honest, very hard-to-fake signal. The gazelle is essentially broadcasting to the predator: "Look at me. I have so much energy and I'm in such good shape that I can afford to do these ridiculous, useless jumps. Chasing me will be a waste of your time." And the research shows that predators are less likely to chase a gazelle that stots vigorously. Mark: That's amazing. The signal is believable because it's costly. A sick or weak gazelle couldn't pull it off. So what's the human equivalent of stotting? We're not jumping up and down in meetings, I hope. Michelle: Well, maybe we should! But for us, the costs and signals are more complex. Our 'open vigilance' system is constantly scanning for three things. First, the source: Is this person competent and knowledgeable? Second, their motives: Are their interests aligned with mine? Are they being honest? And third, the content itself: Is the argument logical? Does it cohere with what I already know? Mark: So when the author himself got scammed out of twenty euros by a man pretending to be a doctor—a story he tells right at the start of the book—what happened to his open vigilance? Did it take the day off? Michelle: That’s a great question, and it's exactly why he includes that personal, embarrassing story. He admits he got played. The scammer was a master at hacking his vigilance system. He presented himself as a doctor (a cue of competence), he had a desperate, plausible story about a lost wallet (a cue of benevolence, since the author was helping someone), and he even gave him a business card (a physical prop to enhance credibility). Mark: He ticked all the boxes. Michelle: He ticked all the boxes. The system isn't foolproof. It can be exploited. But Mercier's point is that the fact we have a system to hack is what's important. We aren't just open doors with a 'Welcome' mat for any idea that comes along. We're more like houses with locks, and most of the time, those locks work pretty well.

Mark: Okay, I'm with you on the locks. But that brings me back to my original problem. If our locks are so good, why does it feel like our neighborhood is overrun with burglars? Why are we seemingly drowning in misinformation, propaganda, and conspiracy theories? Michelle: This is where the argument gets really interesting, because Mercier claims we've been misdiagnosing the problem. Let's take one of the most-cited examples of mass persuasion: Nazi propaganda. The standard story is that Goebbels's propaganda machine was terrifyingly effective and brainwashed an entire nation. Mark: Right, that's what I've always heard. A masterclass in manipulation. Michelle: But the historical data tells a different story. Mercier cites studies showing that Nazi propaganda was most effective only in places where anti-Semitism was already high. In regions with historically low levels of anti-Semitism, the propaganda had little to no effect. In some cases, it even backfired and increased dislike for the Nazis. Mark: Whoa. Let me get that straight. The propaganda wasn't creating the hate, it was just giving a megaphone to the hate that was already there. Michelle: Precisely. It didn't persuade people to become anti-Semitic; it justified the beliefs of those who already were and gave them permission to act. And Mercier argues the same dynamic is at play with a lot of modern fake news. Mark: So when I see a crazy headline shared online, the person sharing it might not have been 'persuaded' by it at all? Michelle: They might not be. Often, the belief serves a different purpose. It's not about a deep, factual conviction. It's about signaling. Sharing that headline is a quick, easy way to say, "I'm part of this tribe," or "I stand against that tribe." The belief is a social badge, not a scientific conclusion. Mark: That makes a disturbing amount of sense. It explains why arguing the facts with my uncle at Thanksgiving is so pointless. I'm trying to correct a factual error, but he's trying to defend his identity. We're not even playing the same game. Michelle: You're not. And this is where some of the criticism of the book comes in. Some reviewers feel that Mercier, in his focus on our cognitive defenses, is a bit too optimistic. They argue that he underestimates just how skilled and powerful a truly sophisticated manipulator—a demagogue, an advertiser, a con man—can be. Mark: Yeah, it's one thing to say our locks are good, but some people are just really, really good at picking them. It feels like he might be letting us off the hook a little too easily. Michelle: It's a fair point, and it shows the complexity of the issue. His work is a powerful corrective to the "everyone is a sheep" narrative, but the reality is probably a constant battle between our vigilance and the ever-evolving techniques of persuasion.

Michelle: So, when we pull all these threads together, Mercier's argument is a really powerful reframing of a modern anxiety. The problem isn't that we're a fundamentally gullible species. The real issue is that we are using a sophisticated, ancient system of trust evaluation—one that looks for competence, shared interests, and good arguments—in a hyper-modern information environment that has learned how to perfectly counterfeit all those signals. Mark: And it reveals that many of our most stubborn and outrageous "beliefs" aren't really about a deep, considered view of the facts. They're social tools. They're badges of identity, ways of burning bridges with one group to prove loyalty to another. And that's a much, much harder problem to solve than just simple fact-checking. Michelle: It is. Which is why his final plea in the book is so important. He doesn't just present his theory; he turns it back on the reader. He writes, and I'm quoting here, "But, please, don’t just take my word for it. I’d hate to be proven wrong by my own readers." He's asking us to be vigilant, even with him. Mark: That's a powerful challenge. It completely changes how you should look at the next argument you see online. So, for everyone listening, what's the one practical thing they can take away from this? The one filter they can apply? Michelle: I think it's this: next time you see a piece of information that either makes you intensely angry or perfectly confirms everything you already believe, just pause for a second. Ask yourself: What social job is this information doing for the person sharing it, or for me if I share it? That question might tell you more than the headline itself. Mark: A mental toolkit for navigating the noise. I really like that. It's not about being cynical, it's about being discerning. Michelle: This is Aibrary, signing off.