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"That guy is so creepy," we occasionally say about other people.

But what does that really mean and why do we say it?

Our “creepy” reaction is both unpleasant and confusing, and according to one study (Leander, et al, 2012), it may even be accompanied by physical symptoms such as feeling cold or chilly.

What is Creepiness?

Following casual conversation with colleagues about the psychology underlying creepiness, I decided to explore what's been studied about the phenomenon. Given how frequently creepiness is discussed in everyday life, I was amazed that no one had yet studied it in a scientific way. The little bit of research that was at all relevant focused on how we respond to things such as weird nonverbal behaviors, and being socially excluded. These studies did not use the word creepiness, but their results implied that our “creepiness detector” may in fact be a defense against some sort of threat.

Creepiness may be related to the “agency-detection” mechanisms proposed by evolutionary psychologists. These mechanisms evolved to protect us from harm at the hands of predators and enemies. If you are walking down a dark city street and hear the sound of something moving in a dark alley, you will respond with a heightened level of arousal and sharply focused and behave as if there is a willful “agent” present who is about to do you harm. If it turns out to be just a gust of wind or a stray cat, you lost little by over-reacting, but if you failed to activate the alarm response and a true threat was present, the cost of your miscalculation could be high.

We evolved to err on the side of detecting threats in such ambiguous situations.

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Creepiness May be a Response to an Uncertainty about Threat

What, then, does our creepiness detector warn us about?

It cannot just be a clear warning of physical or social harm. A mugger who points a gun in your face and demands money is terrifying. A rival who threatens to destroy your reputation by revealing secret information about you fills you with dread. Most of us would not use the word “creepy” to refer to either of these situations, yet in both cases there is no ambiguity about the presence of threat.

I believe that creepiness is aroused by the ambiguity of whether there is something to , and/or by the ambiguity of the precise nature of the threat—sexual, physical violence, or contamination, for example—that might be present.

Only when we are confronted with uncertainty about threat do we get “creeped out." Our uncertainty paralyzes us about how to respond.

For example, it would be considered rude, and strange, to run away in the middle of a conversation with someone is sending out a creepy vibe but is actually harmless; it could be perilous to ignore your and engage with that individual if he is dangerous. This ambivalence may leave you frozen in place, wallowing in creepiness. Yet this reaction could still be adaptive if it helps you maintain vigilance during such periods of uncertainty and manage the balance between self-preservation and social obligation.

The First Empirical Study of Creepiness

I began by trying to identify the components of creepiness. Since there was no previous body of research to build upon, I decided to pursue this question in a study with one of my students, Sara Koehnke. Our study was unavoidably exploratory in nature, but we had a few hypotheses:

If creepiness communicates potential threat, males should be more likely to be perceived as creepy than females, since males are generally more violent and physically threatening to more people (see McAndrew, 2009). Related to the first prediction, females should be more likely than males to perceive some sort of sexual threat from a "creepy" person. Occupations that signal a fascination with threatening stimuli, such as death or "non-normative" , may attract individuals that would be comfortable in such a work environment. Hence, some occupations should be perceived as creepier than other occupations. Since we hypothesize that creepiness is a function of uncertainty about threat, non-normative nonverbal behaviors and behaviors or characteristics associated with unpredictability will be positively associated with perceptions of creepiness.

We recruited volunteers to fill out an online survey through Facebook, and ended up with a sample of 1,341 individuals (1,029 females, 312 males) ranging in age from 18 to 77 with a mean age of 28.97 (SD = 11.34). In the first section of the survey, our participants rated the likelihood that a hypothetical “creepy person” would exhibit 44 different behaviors, such as unusual patterns of eye contact or physical characteristics like visible tattoos. In the second section of the survey, participants rated the creepiness of 21 different occupations, and in the third section, they simply listed two hobbies that they thought were creepy. In the final section, participants expressed their level of agreement with 15 statements about the nature of creepy people.

Our study confirmed the following:

Perceived creepy people are more likely to be males than females.

Females are more likely to perceive sexual threat from creepy people.

Occupations do differ in level of perceived creepiness. Clowns, taxidermists, sex-shop owners, and funeral directors were at the top of the list.

Unpredictability is an important component of perceived creepiness.

A variety of non-normative physical characteristics and nonverbal behaviors contribute to perceptions of creepiness.

Participants did not believe that most creepy people realize they are creepy, nor did they believe that creepy people necessarily have bad intentions. However, they also believed that creepy people could not change.

The most frequently mentioned creepy hobbies involved collecting things, such as dolls, insects, or body parts such as teeth. Bones or fingernails were considered especially creepy; the second most frequently mentioned creepy hobby involved some variation of "watching," such as taking pictures of people, watching children, , and even bird watching.

The results are consistent with the idea that creepiness is a response to the ambiguity of threat. Non-normative non-verbal and emotional behaviors, unusual physical characteristics and hobbies, or suspect occupations set off our “creepiness detector." Men are considered more likely to be creepy by males and females alike; women are more likely to perceive sexual threat from creepy people.

We have presented our results at several conferences and they have been published in New Ideas in Psychology. I plan to extend my research from creepy people to creepy places: We become uneasy, for example, in environments that are dark and/or offer a lot of hiding places for potential predators and also lack clear, unobstructed views of the landscape. These environmental qualities have been called “prospect” and "refuge” by British geographer Jay Appleton. Fear of and a pervasive sense of unease are experienced in environments with less than optimal combinations of prospect and refuge. In creepy places as with creepy people, I expect to find that it is not the clear presence of danger that creeps us out, but rather the uncertainty of whether danger is present or not.

Suggested Readings

Appleton, J. (1975). The experience of landscape. London: John Wiley & Sons.

Appleton, J. (1984). Prospects and refuges revisited. Landscape Journal, 8, 91-103.

Barrett, H. C. (2005) Adaptations to predators and prey. In D. M. Buss (Ed.), The handbook of (pp. 200-223). Hoboken, NJ: John Wiley & Sons.

Fisher, B. S., and Nasar, J. L. (1992). Fear of crime in relation to three exterior site features: Prospect, refuge, and escape. Environment and Behavior, 24, 35-65.

Leander, N. P., Chartrand, T. L., and Bargh, J. A. (2012). You give me the chills: Embodied reactions to inappropriate amounts of behavioral mimicry. Psychological Science, 23, 772-779.

McAndrew, F. T. (2009). The interacting roles of and challenges to status in human male . Aggression and Violent Behavior, 14, 330-335.

McAndrew, F. T., & Koehnke, S. S. (IN PRESS). On the Nature of Creepiness. New Ideas in Psychology,

Öhman, A., Flykt, A., and Esteves, F. (2001). Emotion drives attention: Detecting the snake in the grass. Journal of Experimental Psychology: General, 130, 466-478.

Szczurek, L., Monin, B., and Gross, J. J. (2012). “The Stranger effect: The rejection of affective deviants.” Psychological Science, 23, 1105-1111.

Zhong, C. B., & Leonardelli, . J. (2008). Cold and : Does social exclusion literally feel cold? Psychological Science, 19, 838-842.