The Highly Sensitive Person in the beginning
In 1996 and 1997 Elaine Aron wrote a popular book entitled The Highly Sensitive Person and published a lengthy journal article about this personality type and its measurement scale.* ** The 27 question scale can be seen at https://www.hsperson.com/pages/test.htm. Before constructing the scale, Aron reached out to individuals who “felt they were highly sensitive to stimulation, introverted, or quick to react emotionally” through notices at her University and publicity from a local paper. She received over 100 responses, and from those interviewed 40 people for 3-4 hours each. From their own descriptions of their feelings and experiences, she compiled the still current Highly Sensitive Person Scale. Looking through it you will be struck by the fact that some questions seem closely related t0 the idea of sensitivity, but others will surprise you. A common type of question, for example is:
“I am easily overwhelmed by things like bright lights, strong smells, coarse fabrics, or sirens close by.”
And– “I make it a point to avoid violent movies and TV shows.”
Others, however include such things as
“I am deeply moved by the arts or music” and “I seem to be aware of subtleties in my environment.”
And somewhat farther afield—“I am conscientious.” And “I try hard to avoid making mistakes or forgetting things.”
At the very least the person who scores highly on this scale is both easily bothered by unwanted external stimuli and very much engaged and pleased by other sorts of stimuli.
Aron felt that these qualities all went together. The person most naturally sensitive to the “subtleties” would also be most bothered by louder and more raucous stimuli. Because of this, they would be most likely to feel overwhelmed at times and need to find a place to be alone and quiet.
As Aron explains it, the fundamental, underlying uniqueness is a different “optimal” level of arousal. It is pretty well accepted that we all have some level of arousal at which we are at our best. Below this we may be lethargic, bored, unstimulated, but above it, and especially well above it, we are stressed, jangled and poorly in control. She says “What is moderately arousing for most people is highly arousing for HSPs (Highly Sensitive Persons). What is highly arousing for most people causes an HSP to become very frazzled indeed, until they reach a shutdown point . . . .
The positive side of this is described this way: “What this difference in arousability means is that you notice levels of stimulation that go unobserved by others. This is true whether we are talking about subtle sounds, sights, or physical sensations like pain . . . The difference seems to lie somewhere on the way to the brain or in the brain, in a more careful processing of information . . . .This greater awareness of the subtle tends to make you more intuitive. . . . This is that ‘sixth sense’ people talk about. It can be wrong, of course, just as your eyes and ears can be wrong, but your intuition is right often enough that HSPs tend to be visionaries, highly intuitive artists, or inventors, as well as more conscientious, cautious and wise people.”* (p7). Being emotionally sensitive is also embedded in this concept. HSPs are thought to be more sensitive and aware of their own feeling, and more affected by the feelings of those around them.
Perhaps the most important point is that not only were these qualities all a part of being “sensitive”, the problems were simply the price to be paid for the strong advantages of sensitivity. This is most clearly stated in a quotation from E. M Forester that appears at the beginning of the Aron and Aron journal article in 1997:
I believe in aristocracy, though—if that is the right word, and if a democrat may use it. Not an aristocracy of power . . . but . . . of the sensitive, the considerate . . . Its members are to be found in all nations and classes, and all through the ages . . . there is a secret understanding between them when they meet. They represent the true human tradition, the one permanent victory of our queer race over cruelty and chaos.**
The choice of this quotation seems to make it very clear that such people are seen as among the best of us. Aron suggests that they pay dearly for this heightened sensitivity, however, in the suffering that may accompany overarousal.
The author feels strongly that this heightened sensitivity is health, not pathology. She is emphatic about the need to separate arousal from fear. In her view, arousal may result from fear—or from many other emotions including love, joy, positive excitement, but the characteristic of easy arousability is separate, in her view, from fearfulness, even though it may make you more susceptible to acquired fear. This is an important part of Aron’s view that these high levels of arousability are not inherently a negative quality.
The first challenge to this new concept was an issue that Aron raised herself, from the beginning. Is it simply a form of introversion? There are certainly many similarities. For example, Aron notes in a Psychology Today article*** “Both introverts and HSPs reflect deeply, like meaningful conversations, and need lots of down time. Thus it is not surprising that 70% of HSPs are introverts . . . “ She goes on to note however, that this means that 30% of HSPs are extraverts even though they still need more down time than do extraverts who are not highly sensitive. Thus, although you can be both introverted and highly sensitive, Aron is convinced that high sensitivity is a separate genetic endowment. Her strongest argument for this lies in the various studies she has done on correlations between introversion scales and the HSP scale. She reports an average correlation of .29, suggesting that they share some properties but are by no means identical concepts.
A similar argument is made for the possible relationship of sensitivity and neuroticism. The author would agree that high sensitivity would increase the probability of the development of anxiety, depression, and other neurotic behaviors, but believes, again, that what is primary is the high sensitivity, with neurotic outcomes being the result of this sensitivity and a stressful childhood environment, rather than an unavoidable development.
Support, contradiction, further developments
A 2006 research study**** took issue with the idea that the HSP scale measured a single factor. Instead, they found a three separate components. The first and strongest was Ease of Excitation (EOS), tapping all the items that suggested that external stimuli, pleasant or not, could be overwhelming. The second was Aesthetic Sensitivity (AES) based on items tapping pleasurable responses to music, art, and related stimuli. The third component was Low Sensory Threshold (LST) which included six items specific to unpleasant sensory stimuli (bright lights, strong smells etc.). These factors did intercorrelate with each other, supporting the idea that they described one overall concept of high sensitivity.
These authors also found that their subfactors correlated with the Big Five factors—Extraversion, Agreeability, Conscientiousness, Openness to Experience and Neuroticism. The really interesting finding is that relationships to the HSP scale varied a lot with each subfactor.In particular Aesthetic Sensitivity had very little relationship to Neuroticism, while Ease of Excitation was the most strongly related to Neuroticism. More surprising, the only relationship to Extraversion/Introversion was a very small one between that measure and Low Sensory Threshold (a surprise). Nothing was found with Agreeableness or Conscientiousness, but Aesthetic sensitivity did correlate with Openness while the other sub-factors did not. This suggested less unity in the items of the HSP scale than had been thought.
Following this, a 2008 study tested the HSP scale along with their own measure—the Adult Temperament Questionnaire—which also measures both sensory sensitivity and sensory discomfort.***** The end result was that their own measures of sensitivity and discomfort had no correlation with each other, suggesting that the sensory discomfort had no relationship to positive sensory sensitivity. Further investigation of the HSP scale convinced these authors that there really were just two factors, which by any name, came down to Aesthetic Sensitivity on the one hand, and sensory discomfort (negative affect or Ease of excitation), with Low Sensory Threshold tucked in as a part of sensory discomfort.
The shifting labels make this hard to follow, but the bottom line is that they disagreed with Aron and Aron’s most basic hypothesis—that it all starts with a genetic difference in High Sensitivity, which then may cause both the main effeact of creative, positive sensitivity, and the sensory discomforts as a sort of side effect.
A more recent study found relationships between (especially) Ease of Excitation and mental health problems, but also between the other three sensory factors (if there really are three) and various of the Big Five Factors******At this point it seems really unclear as to which findings are going to hold up.
Conclusion: Work in Progress:
To me, it doesn’t sound like the original HSP concept is going to stand up without changes. If Aesthetic Sensitivity is really unrelated to the Ease of Excitation and Low Sensory Threshold items in the scale, there is a serious problem. Beyond that, the idea that the emotional and cognitive reactivity of the Highly Sensitive Person is fundamentally independent of neuroticism seems questionable. Either that or neuroticism itself needs redefining. If neurotic anxiety and high sensitivity can produce the identical behaviors, we would seem to be in a sort of labeling swamp!
A lengthy Aron and Aron journal article was published in 2012. ******* The authors include a great deal of new information on animal research in sensitivity, on possible physiological correlates of high sensitivity, and on “crossover interactions”, for which, high sensitivity may be a very good example. If, for instance a highly sensitive person experiences a very bad childhood environment, it is certainly possible that this would be more damaging than it would for a genetically less sensitive person. Interestingly, this suggests, however, that a very positive childhood experience might be taken in more deeply by the highly sensitive than by the less sensitive child with an unusually good outcome..
In other parts of this article they discuss at some length, ways in which their HSP scale might be improved in the light of recent research, but I came away with the impression that HSP, though it may have useful subscales, is still seen as a unitary characteristic.
Readers might find it interesting to think of this in connection to the ever so dominant Big Five Scales. Would HSP be an Uber One scale incorporating the Big Five, or a sixth factor or ???
*Aron, Elaine (1996). The Highly Sensitive Person. New York: Three Rivers Press.
**Aron, Elaine & Aron, Arthur (1997). Sensory-Processing Sensitivity and Its Relation to ntroversion and Emotionality. Journal of Personality and Social Psychology, 71(2) 345-368.
***Aron, Elaine (2011). Understanding the Highly Sensitivy Person: Sensitive, Introverted, or Both? Psychology Today (Online at http://www.psychologytoday.com/blog/attending-the-undervalued-self/201107/understanding-the-highly-sensitivity-person-sensitive-int
****Smolewska, K. A., McCabe, S. B. & Woody, E. Z. (2006). A psychometric evaluation of the Highly Sensitive Person Scale: The components of sensory-processing sensitivity and their relation to the BIS/BAS and “Big Five”. Personality and Individual Differences 40, 1269-1279.
*****Evans, D. E & Rothbart, M. K.(2008). Temperamental sensitivity: Two constructs or one? Personality and Individual Differences 44, 108-118.
******Ahadi, B. & Basharpoor, S. (2010) Relationship Between Sensory Processing Sensitivity, Personality Dimensions and Mental Health. Journal of Applied Sciences 10(7), 570-574.
*******Aron, Elaine, Aron, Arthur & Jagiellowicz, Jadzia (2012). Sensory Processing Sensitivity: A Review in the Light of the Evolution of Biological Responsivity. ) Personality and Social Psychology Review XX(X) 1-21.