There are some things in life that are inherently creepy, like swings that move by themselves in deserted playgrounds, and clowns lurking in sewers. But are there any universal traits that, without fail, make people come across as full-blown weirdos?

That's what a team of psychologists set out to discover in a new paper, which they say is the "first empirical study of creepiness" - and there are some pretty surprising traits that ended up on their list that most of us have probably been guilty of at one point in time (especially if you're into birds). 

"It is the goal of this paper to introduce a theoretical perspective on the common psychological experience of feeling 'creeped out'," write Francis McAndrew and Sara Koehnke from Knox University in Illinois. "In other words, we are attempting to identify the building blocks of this thing we call 'creepiness'."

To do this, they asked 1,342 people of all ages (1,029 females and 312 male) which traits they'd find creepy if a friend was describing meeting someone new to them.

The participants then rated those traits - as well as certain behaviours, professions, and hobbies - on a scale of creepiness, from "Seems like a cool person," to "Get the hell away from that psycho, now." (Or if you want to get technical, from one to five.)

Overall, participants were far more likely to find males creepy than females - which is probably because there were so many females in the study, and females in particular rated anyone who could pose a sexual threat as as super weird. 

The other factors defined as creepy were more random, including anything from working as a taxidermist to laughing at odd times, but the overall result was that anything that made people seem unpredictable was likely to set alarm bells ringing.

Which is further evidence being creeped out has evolved to protect us from potential threats, according to the researchers. 

"The results are consistent with the hypothesis that being 'creeped out' is an evolved adaptive emotional response to ambiguity about the presence of threat that enables us to maintain vigilance during times of uncertainty," they write.

So what can you avoid doing in order to seem like a more stand-up, normal person when meeting new friends? 

Here are some of the features that participants overwhelmingly rated as 'creepy':

  • You're male
  • You watch someone new before interacting with them
  • You touch people a lot while interacting with them
  • You constantly steer the conversation towards sex
  • You ask to take a picture of someone after meeting them for the first time
  • You have very pale skin
  • You're very thin
  • You lick your lips frequently
  • You laugh at unpredictable times
  • You wear dirty clothes
  • You work as a clown
  • You have unkempt hair
  • You collect dolls
  • You collect insects
  • You collect reptiles (collecting anything in general just weirds people the eff out, so maybe don't bring it up on a first date)
  • Bird-watching is a hobby
  • You own a sex shop
  • You have a peculiar smile
  • You stand too close to people

While one or two of those traits on their own probably aren't so bad, if you display more than a couple, it might be worth reassessing your life choices.

Sorry, guys.

The full breakdown of creepy traits has been published in New Ideas in Psychology.