Korea is an industrialized nation. Its people are very ambitious and educated on the whole. But, there are a few beliefs that simply defy rationality. I've read arguments that blame Korea's lack of interest in critical thinking skills and after working with school children and adults alike, I'm pretty willing to agree.
1. Fan Death
Many Korean people truly believe that if one sleeps in a closed room with an electric fan running, they will die. The most common insane explanations for this belief are hyperthermia/ hypothermia and suffocation from a) the fan sucking the oxygen out of the room, b) the fan not allowing one's skin to breath, c) the fan producing carbon dioxide and, my favorite, d) the fan "chopping" the oxygen particles in the air, rendering them useless.
2. Jumping Rope Will Make Me Taller
All of our students wholeheartedly believe that no matter their genetics, jumping rope will make them taller. I'm not here to discourage the past time (bone density is important for everyone and jumping rope DOES help with that), but I can't help but feel bad for the little kids and their poor body image. If you want a little proof about the Asian community's stock in this belief, do a simple Google search. I found entire forums dedicated to it. On a side note, it seems that girls are sometimes told that cutting their hair short will help them grow tall.
3. Vaccinations + Shower = Potentially Fatal
In Korea many people believe that if you shower within 24 hours of a vaccination you may die. I don't know much about this myth, but it seems in line with some of the others.
4. Surgery Helps Kids Speak English
All of the articles I found on this were at least five years old. Hopefully, it's fallen out of fashion. Apparently, the operation involved cutting the tissue connecting the tongue and lower jaw. Cosmetic surgeons advertised that the procedure could help children with some of the trickier aspects of the English language, like the subtle difference between an 'r' and an 'l.' Unfortunately, the problem for many Korean English students is that they try to pronounce the 'r' sound with too much tongue, not too little.
5. Rubbing/ Pinching the Bridge of Your Nose Will Help it Develop and Lengthen
Koreans seem to be self conscious about their noses. To many of them, a good profile is key to beauty. Nose jobs are one of the most common elected facial surgeries in South Korea. New mothers will rub or pinch their babies noses, thinking it will encourage growth and give way to her desired shape. Some young kids are taught to rub their noses on their own. This myth also extends to eyes (gentle rubbing for larger eyes) and legs (pulling and rubbing a babies to make them grow tall).
There are many, many more. The superstitions regarding pregnancy and childbirth could fill a book. I encourage you to Google search it.