A friend brings you to a party where you don't know anyone, but you want to make an impression on the next person you meet. Your friend hugs a friend and introduces you. Do you hug them, too?
Stop right there. Scientists from the University of Oxford and Aalto University in Finland have your back. Their advice? Stick to handshakes.
In a new study published in the Proceedings of the National Academy of Sciences, researchers surveyed men and women about where they feel comfortable being touched by different people and found that, when it comes to strangers, there's only one place people are OK with being touched: their hands.
On the body map below, yellow and white areas indicate where people said they would feel comfortable being touched, while red to black areas show where respondents said they would be uncomfortable. The respondents were comfortable with being touched by their partners pretty much anywhere on their bodies, while male and female strangers could only touch their hands, as indicated on the very far right of the graph.
PNAS
The blue lines (outlining the crotch and the buttocks in many cases) indicate "taboo zones," where absolutely no touching in that area would be comfortable. The "tabooo zone" is larger for strangers than anyone else.
The study is the largest ever done on physical touch, the researchers wrote, with 1,368 respondents from Finland, France, Italy, Russia, and the United Kingdom.
The gender of the subject and the toucher played a huge part in that discomfort. The researchers found that the respondents were more comfortable being touched by women, including female strangers.
This is especially true for the male subjects. The body map below shows that men were generally open to female acquaintances and strangers touching them on more areas of their body, whereas much of their body but their arms and chest were closed off to male strangers (the far-right column, where "stranger" is in blue).
PNAS
According to the study, both male and female participants felt their relationships with women tended to be stronger, which may reflect their comfort with being touched by women, even if they're strangers.
"Touching is an important means of maintaining social relationships," Julia Suvilehto, a researcher from Aalto University, told The Independent. "The greater the pleasure caused by touching a specific area of the body, the more selectively we allow others to touch it."
The researchers gathered the participants' responses using an online survey. They were asked to use a mouse to paint the areas of the body where they'd be comfortable being touched by each member of their social network.
The findings might be limited to Western cultures. And of course, comfort levels vary from person to person; the averages from a group won't tell you what's comfortable for any particular individual.
Either way, it's probably best to just not touch people you don't know.