Usually, when you think of contagions, you tend to think about 18th-century illnesses and disease, or an especially wet cougher on the subway. But in truth, there are several surprising things that are contagious, both medically and psychologically, that you'd never expect to spread so easily from one person to the next. It's an obvious statement that we're all, in one way or another, affected by the things around us, but you might not have ever known you were this influenced by, say, your friend who just quit smoking cigarettes, or your stressed-out roommate.
In truth, certain feelings, sensations, and even emotions can sometimes be every bit as contagious as a head cold or a rash. What makes this whole situation a little bit more challenging is that, yeah, you might know how to avoid catching the flu (by washing your hands, for example, and avoiding crowded areas), but it's much harder to avoid "catching" a feeling, especially when you don't even know what the source of your feeling really is.
The more researchers learn about the way humans interact with one another, the more clear it becomes how heavily people are affected by the communities they spend time with. So you might want to think about what types of emotions and energy you're giving off to your friends, because you never know what they're going to catch, or vice versa. Here are seven totally surprising things that can actually be contagious.
01Feeling Cold
Surprisingly enough, temperature can be contagious — sort of. According to research published by the journal PLOS One, people who watched a video of a hand getting dipped in cold water suddenly felt colder themselves than when they watched a video of someone's hand getting dipped in warm water.
What's more, the study participants' hands actually reflected a small temperature change, dipping when they watched the cold water video. So yeah, when your friend shivers in front of you, that shiver might just be contagious.
02Your Friend's New Shoes
Everyone knows envy can be passed around pretty easily, but you might be surprised to know that you're more likely to want an object simply by virtue of someone you know having it, too. A 2012 study published in the Journal of Neuroscience revealed that people are more likely to want an object (like a pair of shoes or a piece of jewelry) if they see that this object is desired by another person.
It's called "mimetic desire," according to the research, and it pretty much explains why you and your sister fought over the same shirt every week growing up, even though you both had plenty of other pieces of clothing to wear.
03Cavities
This one's pretty gross: The bacteria that leads to cavities can be passed around through kissing, sharing toothbrushes, or (if you're a mother) from tasting your child's food before passing it to them, according to TIME.
The outlet says the easiest way to avoid this is, obviously, to ramp up your dental hygiene, brushing twice a day and even considering mouthwash after you've kissed someone whose dental hygiene habits are a bit more questionable.
04Ringworm
You know those towels you use when you go to the gym? Well, you might be dealing with a pretty upsetting contagion if you use them. According to Prevention, that rash in the shape of a ring with normal skin in the center might just be ringworm — and it can easily be passed through objects like towels, or through direct skin contact. Play it safe and try to bring your own towel to the gym next time.
05Stress
According to a 2014 study done by researchers in Germany, observing another person who's in a stressful situation can make you feel stressed out yourself. Even watching people who are stressed out behind a screen can ramp up your own stress levels — which is why I personally want to remind you to be prepared to feel a rise in your heart rate while you watch the new season of The Handmaid's Tale. Just saying.
06Loneliness
It's true: According to research published in the Journal of Personality and Social Psychology, loneliness can easily spread from person to person, and apparently, it often occurs in "clusters" in various social circles. The researchers wrote that their findings suggest, in order to combat the spread of loneliness, it's important to protect "the people in the periphery," meaning the people within your social circle, and try to address their loneliness, which in turn will help create a "protective barrier against loneliness that can keep the whole network from unraveling."
07Quitting Smoking
According to a 2008 study published in The New England Journal of Medicine, if your friend quits smoking, it apparently makes you 36 percent less likely to keep smoking yourself. This might be part of the reason why addiction support groups are so helpful: While bad habits are contagious, some good habits might be contagious, too.
If you're looking to quit a habit, whether it's smoking or something else, try spending time with a person who's kicked that habit themselves. They might have some good advice for how to do it, and who knows — you might feel better just by being around them.
