Smacking, the noise you make while eating, is a controversial part of the human dining experience. Some cuisine cultures encourage people to make noise when they eat. It is considered a compliment to the chef, when the diner slurps his soup for example. But other cuisine cultures think it is the absolute rudest act you can commit at a dinner table. It’s ruder than putting your elbows on the table – that’s right, it’s bad. It’s not just rude though, it’s aggravating to some people, to the point that it might just start a fight. You might think this is an overreaction, but recent research has finally shed light on why it is so aggravating (and justified why you need to stop smacking at the table).
For some people, the sound you make when smacking actually triggers a complete flight or fight response – that survival instinct that kicks in when you’re in danger. This is caused by “misophonia”, a condition that makes people sensitive to sounds. It actually occurs in people whose brain is wired differently. When people with misophonia hear smacking, it actually can trigger sweating and increase their heart rates. Those are classic signs of flight or fight. Looking at brain scans in studies done on people with misophonia shows that these people have different neural pathways in the anterior insular cortex.
People born with misophonia is definitely rare, so you’re not scaring everyone to death with your smacking noises. But for people who do have it, it’s like you’re constantly telling them they’re under assault. Just think about that next time you’re happily smacking your lips together why you eat. Chewing with your mouth closed also stops us from having to look at your food mashed up inside your mouth. Preventing us from seeing that is just a bonus.