OPEN POST: According to Science These Are The Scariest Movies of All Time

According to the "Science of Scare" study, the top 20 scariest movies of all time, in order, are Sinister, Insidious, The Conjuring, Hereditary, Paranormal Activity, It Follows, The Conjuring 2, The Babadook, The Descent, The Visit, The Ring, A Quiet Place, A Nightmare on Elm Street, Halloween, The Texas Chainsaw Massacre, 28 Days Later, The Exorcist, Hush, It, and Scream. The study invited 250 people to watch 40 feature films that are among the best horror films according to expert critics in the field. The team measured the average impact the shortlisted movies had on the heart rate, measured in beats per minute, and heart rate variance, which is the time between each heartbeat. They used this measurement to assess how stressed audience members might become while watching the film, making it "a good indicator of slow burn fear and dread." They combined the two metrics to create a "Scare Score" and determine which scary movies have the biggest impact. The highest possible score is 100. Modern horror movies performed better than classics, with just three films more than 20 years old appearing in the top 20.

I am not an expert but Sinister had my heart doing flip-flops.