Take a close look at this research by Knox College psychology professor Frank McAndrew and one of his students.

Just don't get too close: that would be "creepy." 

Research into "creepiness" was conducted by Frank McAndrew and one of his students, Sara Koehnke, and recently published in the journal New Ideas in Psychology. Media worldwide have glommed onto their study of the feeling you get when something feels weird.

In the article, McAndrew and Koehnke wrote that feeling "creeped out" is a "universal human response" to uncertainty.

Coverage includes:

• Today Show: "Creepiness is all about not being able to figure out whether there is a threat."
• Washington Post and other media: "Many people think birdwatchers are creepy... don't point your binoculars at other people's houses..."
• Vice.com: "High predictors of creepiness included standing too close... "
• Daily Mail, UK: "Experts reveal the behaviours, hobbies and jobs that give people the chills..."
• Conan O'Brien: "That's so creepy!"
• Discover Magazine: "Uncommon physical characteristics contributed to perceptions of creepiness."

"It is our belief that creepiness is anxiety aroused by the ambiguity of whether there is something to fear or not and/or by the ambiguity of the precise nature of the threat (e.g. sexual, physical violence, contamination, etc) that might be present," wrote McAndrew and Koehnke.

Knox College reported on the research and earlier coverage in media including Business Insider and Smithsonian Magazine, in a 2015 article: Research Defines "Creepiness"

Originating as Koehnke's senior research project in psychology in 2012, the survey gathered more than 1,300 responses of women and men between the ages of 18 and 77 who were asked about physical qualities or lifestyle choices that would be seen as creepy.