Throughout human history, one type of story never seems to go away: the conspiracy theory.
Conspiracy theories may seem like a modern epidemic — a byproduct of social media algorithms and a 24-hour news cycle. But according to Kathryn Olmsted, a distinguished professor of history at UC Davis with expertise in conspiracy theories, that isn’t the case. “They’ve been very common in the past, throughout history in all different cultures and throughout the world today,” she said.
When researchers compare how conspiracy-minded different countries are, the United States actually falls somewhere in the middle. There’s also little evidence that individual beliefs in conspiracy theories increased on average over time, partly due to the lack of conspiracy theories in research before 2010.
“They’re a lot more in our face now because of social media, so they seem more prevalent,” Olmsted said. “It’s really hard to measure, though.”
Here, Olmsted answers common questions about conspiracy theories.
How have conspiracy theories changed?
Nineteenth-century America produced conspiracy theories geared toward minority groups. Anti-Catholic conspiracies were particularly lurid: Catholics, so the theories went, were stealing children. Mormons, freemasons, and secret societies, like the Illuminati, were frequent targets.
The character of conspiracy theories began to change around World War I, a period Olmsted examined in her 2009 book, Real Enemies: Conspiracy Theories and American Democracy, World War I to 9/11. The war brought about an expansion of the federal government, and anti-government theories about secret groups controlling the republic from within became increasingly prominent.
Today’s landscape is a continuation of past patterns, amplified by the growth of the federal government.
What causes conspiracy theories?
In the aftermath of tragedy, disaster or unresolved mystery, conspiracy theories offer internally consistent explanations that allow people to make sense of events. Research suggests that belief in conspiracy theories is especially strong when events are large in scale, historically significant or leave people dissatisfied with mundane explanations. Some researchers have described this as the need for “cognitive closure.”
“When there was an intelligence failure by the government, or in other words, something bad happened to the people in the United States,” Olmsted said, “there would then be conspiracy theories.”
Conspiracy ideation reflects a feeling of diminished control over circumstances. Just as the idea of “luck” simplifies a complex situation into something the mind can manage, a conspiracy theory imposes order over chaos.
In a 2004 poll, 49% of New York City residents reported believing the U.S. government was somehow complicit in the Sept. 11 attacks. “People who are especially worried about having security in their lives are more inclined to believe conspiracy theories,” Olmsted said, “because they would prefer to believe that there is a small group of evil people in charge of the world than that bad things just happen.”
Simply put, when people feel their sense of control or certainty is threatened, they might turn to conspiracy theories.
Why do some conspiracy theories spread more than others?
Hundreds of 9/11 conspiracy theories have circulated in the last two decades, but only a handful captured widespread attention. The controlled demolition theory, which alleged that the World Trade Center buildings were brought down by pre-planted explosives rather than the impact of the planes, became perhaps the most widely circulated. A focal point for this theory was the collapse of Building 7, the third tower to fall on Sept. 11, despite not being struck by a plane.
Conspiracy theories, as researchers have noted, tend to thrive in the gaps. BBC News reported the collapse of Building 7 20 minutes before it actually fell. Some researchers claimed to find traces of explosive material, specifically “nano-thermite,” in the presence of molten steel after the collapse. Eyewitnesses recount horizontal puffs of white smoke during the collapse, attributing them to the work of explosives. These “gaps” explained by the controlled demolition theory account for its popularity.
International responses illustrated another key dynamic: Theories must align with a person’s existing beliefs and worldview. An Ipsos-Reid poll showed that 22% of Canadians believed the 9/11 attacks were a plot by influential Americans and had nothing to do with Osama Bin Laden. A popular account in several Muslim-majority countries held the attacks were the work of the U.S. or Israeli governments. Both examples reflect the same underlying dynamic: The theory that resonated was the one that fit a preexisting worldview. Canadians are consistently polled to believe anti-American government conspiracies more frequently to their own, and Islamist circles would be skeptical the attacks were an American attempt to demonize Muslims.
The controlled demolition theory remains popular even years after the official report from the National Institute of Standards and Technology, which concluded that the building’s collapse was due to the effects of burning nearly seven hours, leading to the collapse of the 13th floor and weakening of a critical support column, and detailed the near-impossibility that thousands of pounds of explosives were snuck past security and placed within the towers.
Perhaps the most telling argument against this theory is how, despite the hundreds of people allegedly complicit (if you had to acquire and plant the explosives and arrange for the airplanes to crash), no one has spoken a word about it.
“What are the most popular conspiracy theories?” Olmsted asked. “Well, conspiracy theories that appear to give people a sense of control and mastery over an otherwise chaotic universe.”
What are the dangers of conspiracy theories?
Not all conspiracy theories are equally consequential. Some are built off humor, like those in which famous celebrities have been replaced by lookalikes.
But Olmsted is clear about the real dangers. Climate denial may have severe long-term harm. Theories that discourage medical care have direct consequences, both for individuals and for communities that depend on immunizations. They also prey upon a distrust for medical experts. Theories that cast suspicion onto minority groups, like immigrants, can generate social conditions for discrimination and violence.
The environment of a conspiracy theory can also affect a believer on the psychological level. Unlike legitimate investigations, conspiracy theories are often built to be impossible to disprove. Any contradicting information or absence of evidence are used as proof of the cover-up, rather than a reason to doubt the theory.
Unfailingly, such beliefs lead to dead ends, and the uncovering of conspiracy plots is left to investigative journalists, whistleblowers, or state-sponsored inquiries. This unwavering belief, however, can cause an individual to withdraw from society or take extreme action.
“In theory, conspiracy theories about the government could be helpful because they make people skeptical and demand answers, but lots of times they are not,” Olmsted explained. “Instead, people just become deeply cynical and decide, well, I’m not going to vote anymore because it doesn’t matter.”
How do I talk to someone who believes a conspiracy theory?
Olmsted offered two practical tips for those who want to engage with someone who believes a conspiracy theory. First: Do not engage with the theory itself. Challenge the facts, but value their argument. Address specific claims, and offer to look through credible sources together.
Second: Never ridicule. “If you are dismissive or attempt to indicate that this person is just not very smart or very well-informed, and that’s why they believe the conspiracy theories, they’ll shut you out immediately,” Olmsted said.
Be realistic in your interventions. The most you can do is set up a believer for success by providing them with the tools they need to make critical decisions. Overall, interventions that foster an analytical mindset or teach critical-thinking skills are found to be the most effective in changing conspiracy beliefs.