There has been very little writing or research about this experience. A 2016 study by Francis McAndrew and Sarah Koehnke, published in New Ideas in Psychology, is the only one you will find if you Google the topic. It seems to find creepiness to be a variant of anxiety and bases the distinction between the creepy and the anxiety-provoking largely on the ambiguity, as opposed to the certainty, of the threat in the former:
‘…[G]etting “creeped out” is a response to the ambiguity of threat and that it is only when we are confronted with uncertainty about threat that we get the chills.
For example, it would be considered rude and strange to run away in the middle of a conversation with someone who is sending out a creepy vibe but is actually harmless; at the same time, it could be perilous to ignore your intuition and engage with that individual if he is, in fact, a threat. The ambivalence leaves you frozen in place, wallowing in discomfort.
This reaction could be adaptive, something humans have evolved to feel, with being “creeped out” a way to maintain vigilance during a situation that could be dangerous.’
A recent episode of the podcast Stuff to Blow Your Mind dissected the concept of the creep and took a similar tack.
I was surprised that this conception of the creepy never mentions another deeply innate aversive emotion distinct from fear or anxiety — namely disgust or repulsion, which I think plays a part in the experience of creepiness which cannot be ignored.
Let’s start with the ‘origin myth’. The concept of creepiness may have arisen from a visceral experience. Someone or something is creepy if it “gives us the creeps.” This sensation is distinct from the visceral experience of fear, which involves autonomic arousal. When we are creeped out, we are not merely afraid. As I experience it, creepiness combines the spine-tingling and the sickening or queasy. It is not simply a variant of fear, but somewhere between fear and disgust and, I would argue, often much closer to the latter.
There are various reasons we find something aversive. If it presents a threat to our safety or bodily integrity, it stimulates anxiety and the ‘fight or flight’ syndrome. Regardless of whether it is a definite danger or merely one of sufficient likelihood, it stimulates the same reaction. There is no different emotional experience associated with an ambiguous threat, if it crosses some probability threshold of threat assessment. Thus, on its own, I find the idea that the distinction between the fearful and the creepy is based merely on the ambiguity of the threat an insufficient explanation.
In contrast, disgust operates to make us avoid those things that might make us physically ill rather than those that might simply harm or injure us. Unlike fear, disgust is protecting us against our own appetites. A food or a sexual encounter is pleasant, but if we are not protected by disgust we will not avoid creepy foods or sexual encounters which might sicken us. Sexual violence is violence done to us in the course of an act we are otherwise prone to enjoy, whereas the same is not true of nonsexual violence like a mugging. That is the basis of the studies and thinkers that find the essence of creepiness to be in the ambiguity of the threat, as discussed above. The threat when we are repulsed by something is ambiguous because our aversion is struggling with our own appetite to something similar to those things that normally attract us, in a way it does not when we are simply afraid of something.
Although equally aversive in purpose, disgust is a distinct experience from fear, serves a distinct purpose, and developed evolutionarily as a distinct mechanism with a distinct neurobiology. In several psychological typologies of basic emotion, e.g. those of Robert Plutchik or Paul Rozin, disgust is distinct from other emotions such as fear, anger and sadness; it is a different archetypical emotion. Paul Ekman says that it invokes a distinct and characteristic facial expression, one of the universal facial expressions of emotion. Physiologically, while fear causes tachycardia and hypertension, disgust drops the heart rate and blood pressure. Changes in skin conductance and respiratory control differentiate the two states as well.
Functional MRI studies have correlated the experience of disgust with the activation of the anterior insula, quite distinct from fear, whose neural correlates include various cortical regions and the amygdala. Lesions of the anterior insula lead to deficiencies in experiencing disgust and also in recognizing it in others. It would be interesting to do fMRI studies of subjects exposed to something they find creepy and see if the consequent neural activation is closer to the fear experience or the disgust experience.
Behavioral studies have found that disgust is elicited, across cultures, by: bodily products and secretions; spoiled foods; disease-bearing animals; visible dirt; violations of the body envelope (blood, gore, mutilation); visible signs of infection or bodily distortion; death and decay. The aversion to pathogens inspired by disgust has been referred to as the behavioral element of the body’s immune system, causing us to avoid contracting disease or contamination rather than having to fight it once infected or contaminated.
In the zombie oeuvre, doesn’t the zombie become creepier and creepier the more decayed and disgusting s/he is? The reanimated newly dead, at first, are merely threatening, not creepy.
Social norms function to protect us from harm, and there are distinct but equally important social norms against both* violent antisocial behavior* and against uncleanliness and disease. The threateningly creepy person, as opposed to the merely threatening one, threatens to violate different social norms which have more to do with contamination and impurity than merely dangerous antisocial behaviors. These are an important, if covert, source of many of our social mores, as argued forcefully in Mary Douglas’ masterful Purity and Danger. Disgust thus has a role in enforcing certain forms of morality. Disgust functions to apply to social contaminants as well as physical ones, inspiring social avoidance as well as other aversions. We shun or expel the moral reprobate much as we avoid a physically disgusting stimulus like a pool of vomit. We refer to criminals with such terms as “slime” or “scum.” The creep, I would argue, is someone who inspires moral disgust.
Some of the cultural differences in what is disgusting — and what is found creepy — can thus obviously be seen in terms of the distinct social norms across cultures. It is perhaps no accident, from this point of view, that the ostracized lowest class in Indian society are “untouchable.” Creepiness may entail a flavor of ethnic otherness. This should be seen in light of the danger of impurity — often, the ethnic other has been seen as unclean and diseased. (If greasy hair is seen as the creep’s attribute, it is because his appearance inspires disgust of his dirtiness and potential disease, I would argue. ) Indeed, research has shown that people more sensitive to disgust tend to make stricter moral judgments. They find their social in-group more attractive and have more negative attitudes toward others. Interestingly, in some studies people of different political persuasions have different fMRI activity patterns in response to disgusting images even if reporting similar conscious reactions to the images. In one study, the reaction to a single image could predict a person’s political persuasion with 95% accuracy.
FMRI studies also show that, when viewing images of people from stigmatized groups that inspire disgust (homeless, drug addicts), subjects have reciprocally reduced activation of brain regions associated with the experience of empathy. Stereotyping, xenophobia, and dehumanizing of the outsider may be based on the neurology of disgust or creepiness. Ethicist Martha Nussbaum, for example (From Disgust to Humanity), argues that the “politics of disgust” supports sexism, racism and antisemitism and that disgust is employed to enforce oppression. She and others argue that it is urgent that reactions of disgust to social others be rebutted.
Women more often react to others as creepy. Studies have shown that women generally report greater disgust than men as well, especially regarding sexual disgust. Interestingly, disgust rises during pregnancy, perhaps mediated by increasing levels of progesterone. (Do innate differences in sensitivity to disgust correlate with progesterone levels even in nonpregnant individuals?) Some have conjectured that this behavioral avoidance (“behavioral immunity”) is a compensation for the pregnant mother’s need to dial down her immune system so as not to attack or reject the embryo. As the immune system is weakened, disgust becomes a more important line of defense.