The way your body reacts to fear is actually much more intricate than you think as it can actually determine your safety or it could just curdle your blood the next time you’re watching that serious Horror movie.
Lovers of horror movies will definitely be familiar with the term, “blood-curdling scream” that you probably have let out at one time or the other when watching a scary movie.
But according to a group of Dutch researchers, no one realized how accurate the term “blood-curdling” is: Fear can literally cause your blood to curdle.
In the study, published in British journal The BMJ, researchers recruited 24 healthy volunteers aged 30 or younger. Fourteen of the volunteers watched a scary movie (Insidious), and then a week later a light, educational movie (A Year in Champagne). The remaining volunteers did the reverse, watching the tame movie first, and then the suspenseful one.
Researchers found that while watching Insidious, the volunteers’ levels of factor VIII—a protein that plays a role in blood clotting—jumped by enough to raise their risk of blood clots.
57 percent of the volunteers experienced the jump, while just 14 percent experienced an increase during the educational movie.
The researchers believe that there is a good chance humans evolved the clotting response when they experience fear. A blood clot is the body’s response to injury, and it can slow or stop bleeding.
Furthermore, a blood clot is a combination of platelets in the blood combined with specific proteins in your blood to form a solid plug to prevent further bleeding.
When you get scared, the most primitive part of your brain takes over causing the flight-or-fight response. Your body releases adrenaline, pupils dilate, and blood vessels located in our extremities constrict moving blood to vital organs and muscles.
The body also prepares itself by elevating factor VIII in the blood to increase the body’s ability to form clot in case of blood loss or injury. This instinctive response doesn’t know the difference between being chased by a bear or watching a frightening movie, and as such responds the same way.
However, the study authors concluded that the increase is unlikely to cause actual clot formation. What this means is that you can enjoy your favourite movie genre knowing your body is primed to form a clot in case you scrape your shin on your centre table jumping off the couch in fear.