Olivia O’Neill in “The Exorcist: Believer”.Photo:Universal Pictures/Everett

Universal Pictures/Everett
It may defy belief thatThe Exorcist: Believeris based on real events — but according to its technical advisor and creative consultant, audiences should cast out their doubts.
“These are real phenomena,” claimsChristopher Chacon, an expert who consults on both real-world possession cases and Hollywood’s screen adaptations of such. “All the elements we put inThe Exorcist: Believerare very authentic and [based on] these experiences that people have encountered.”
And those experiences aren’t second-hand. Chacon himself has seen disturbing human behavior around the globe that remains — given the rigorous process of elimination he applies to each case — unexplainable. “I’ve seen it demonstrated and take place in real life,” he tells PEOPLE exclusively. “Not only that, but we’re able to scientifically assess it and analyze it. And even with state-of-the-art technology, you still have no answers because you’re dealing with something that science can’t measure in every way.”
Christopher Chacon.Courtesy of CEM

Courtesy of CEM
The most accurate terminology to describe all the above is “preternatural phenomena,” he says, adding, “It’s not supernatural. It’s just that we don’t understand these phenomena.”
After meeting and collaborating with parapsychologists Scott Rogo, Loyd Auerbach and William Roll, Chacon joined the “anomalistics division” of a Silicon Valley scientific think tank comprised of scientists studying “everything from astrophysics to zoology,” he says.
OnThe Exorcist: Believer, for example, Chacon helped director and cowriterDavid Gordon Green“find a cohesiveness for the vision of it.” He adds, “I’m giving them whatever I can to enhance the authenticity.”
(Left to right:) Lidya Jewett and Olivia O’Neill in “The Exorcist: Believer”.Universal Pictures

Universal Pictures
Investigating cases offscreen, however, requires providing a different — and “very unbiased” — kind of perspective. “There are thousands and thousands of cases being reported,” according to Chacon. “The only ones that get forwarded to me is when the phenomena is extreme. They are at their wit’s end in how to define it.”
Before he agrees to travel to check the phenomena himself, Chacon says the individuals or institutions contacting him must “rule out explainable phenomenon: psychological elements, physiological, environmental, and of course, hoaxes. They have to do background checks on the people involved.”
For occult-related cases, “70 to 80 percent have a rational explanation.” Misperceptions abound, he adds, especially among “religious groups [who] have a tendency to see things black and white when something might look malevolent.” Part of traveling the globe to approach each investigation with a scientific method means remembering that “every area has their own culture and belief system” that may affect their interpretation of different phenomena.
Fans of1973’sThe Exorcistand its follow-ups will no doubt recognize such stranger-than-fiction details. As Chacon points out, the box office success of that Oscar-winning film comes from its “very grounded” approach to the unexplainable events it depicts “almost as a documentary.”
“All the phenomena, the ritual, how people react, it’s all accurate, the way it really is,” he continues.The Exorcist: Believertakes the same approach, although, he acknowledges, “the phenomenon is much more disturbing than the original one.”
Yet, as Chacon notes, “They did an incredible job of recreating that, putting that chemistry together, of creating that feeling of being grounded. It gets under your skin emotionally.”
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Linda Blair in 1973’s “The Exorcist”.Warner Bros./Everett

Warner Bros./Everett
According to Chacon, belief in unexplainable phenomena is on the rise. “There’s a growing percentage of people who said they saw an exorcism or saw someone who was possessed,” he claims.
It explains why each Halloween audiences flock to theaters for, as Chacon says, the “chemical rush that happens in the safety of our seats.” There’s an additional satisfaction, he adds, in knowing what’s on screen is just pretend — unless, of course, it’s convincing enough to make a believer out of them.
When asked whether the phenomena depicted in anExorcistmovie is authentic, he struggles to answer because Hollywood magic is “all fantasy.” Chacon says, “It’s really hard for someone to grasp the idea that that [on screen is] real. That can actually happen, that kind of phenomena. It’s not supposed to happen in real life.”
source: people.com