The old-fashioned expression “blood-curdling” is still used to describe anything extremely scary, but according to a scientific study recently published in the British Medical Journal, that term might e accurate: watching horror movies can literally trigger a measurable change in your blood.
The study, entitled “Bloodcurdling Movies and Measures of Coagulation: Fear Factor Crossover Trial,” was overseen by Banne Nemeth at Leiden University in the Netherlands, conducted by several doctors and published in the BMJ’s Christmas Edition. The publication usually picks a more festive subject for the holidays, so this was kind of a bizarre choice… still, it’s apparently no joke; the results were scientifically verified.
The results were tabulated after a group of 24 healthy volunteers were shown two different films: Group A watched A YEAR IN CHAMPAGNE, a documentary about wine-making, and Group B watched INSIDIOUS. That title wasn’t picked at random, either: INSIDIOUS was singled out from other horror contenders for being “consistently scary.” Blood tests taken 15 minutes after viewing revealed that the INSIDIOUS audience had higher levels of protein factor VIII, a blood-clotting agent.
Nemeth, a specialist in venal thrombosis, said that his research was inspired by the term “blood-curdling” itself, which references fear and terror in multiple languages (bloedstollend in Dutch; das Blut in den Adern erstarren lassen in German; and à vous glacer le sang in French). He decided to find out whether the term had any truth to it… and as the results proved, it totally does.
Nemeth theorizes that the connection between fear and coagulation of blood might be a product of natural selection: “We think that from an evolutionary perspective it is actually a good thing to clot a bit faster if you experience fear,” he noted. “Fearful situations often come together with trauma or injury… it would be good to prepare your body for blood loss.”