For this blog, instead of a straightforward summary of what I see as the best of the latest research, I am going to explain more about the old and new measures of high sensitivity, AKA Sensory Processing Sensitivity (SPS), because most of the latest research is still based on the old measure, which is, well, inherently flawed in certain ways, although not fatally so. Indeed, the two scales give similar results, overall. Which is great.  But the flaws have become a serious problem.

If you are really interested in the research on SPS, it is very important that you read this rather long blog post carefully.

I began explaining to you the new measure back in December here, when it first appeared on my website and Michael Pluess’s site here, I told a bit about how we created it, carefully, and that it is shorter, eighteen items, and has six factors, with a nice balance of positive and negative factors and items. The six factors, with three questions (“items”) in each, are Sensitivity to Details, Depth of Processing, Social Sensitivity, Sensitivity to Positive Experiences, Emotional Reactivity, and Overstimulation. Nice, yes? 

But, Yes, a Scale of 1 to 7 is Inconvenient When Taking it on Paper—Why Was That Done?

Actually, the old HSP Scale also used a 1 to 7 scale for research, but it being much longer, on our website and on paper for clinical use, it seemed okay to just use true/false or yes/no.

But there is no shorter version of this scale, so each item must be rated on a scale of 1 to 7, as I will explain.  This is no problem if you take it on one of the websites.  But if you are an individual or a mental health professional wanting to give or take this test on paper, it means you have to add up 18 different numbers.  Why was it done this way?

I need to start with the fact that this measure (like most valid psychological measures) was created for research purposes, not for diagnosing or categorizing an individual. (I always think deciding on an individual’s sensitivity should involve more than a self-report questionnaire anyway.) The research function of the measure is much enhanced by using a scale of 1 to 7, called a Likert Scale. You can see why.  Each answer is more precise than just a yes or no. That allowed us to use only 18 questions to cover all 6 factors, 3 questions for each–short enough for a researcher to include it in a study and have other measures in the study too. (And if a clinician gives the measure by reading out the questions from each factor and getting an answer that falls between “never” and “extremely,” that gives a more precise picture of the individual.)

Okay, What Is a Factor?

It is very important as you read this post that you understand what a factor is within a measure. A factor is uncovered statistically within the full list of items in a measure by looking for items that group together—that is, if those filling out the measure said yes or answered with a high number to one item and then on another they were very likely to say yes or give a high number, and then on another, but answered lower on others, those on which people gave similar answers are seen as a subgroup of items within the measure that can be grouped together as a factor. Then each factor is given a name. Think “aspect” or “major characteristic.” 

Factors can be deliberately created when making a measure, as we did for our new measure.  That is, a researcher can create items that, if you answered high on one, you were likely to answer high on other, similar items.

If I were creating a measure to help a city person know if an animal in a pasture is a horse, cow, goat, lama, or whatever, I might ask Qs about the height, the number of legs, the length of the hair, the type of tail or hooves, and also questions about behavior—does it often run, climb, approach people, make noises, does it seem like it can be ridden. So there would be sets of items that would create an appearance factor and another set of items would create a behavior factor. Back to the factors in measuring high sensitivity in a moment.

Did We Really Need a New Measure?

People tell me that when they take the new measure they come out about the same as when they take the old one. That’s really excellent news, actually. We hoped the new measure would work the same, so that past research studies that used the old measure were not invalidated. But there are two problems with the old measure—one is what the measure says about the trait, and the other is its factors.

In a way a measure is like an inventory, or even an advertisement for the thing being measured. Reading the items, you come to understand the thing it is measuring. Back to my measure of what-animal-is-it, my items so far are very factual, but I might include questions that ask about the animal’s beauty–how much people think this animal is nice to watch; how much are its ears small and delicate or large and floppy; how soft is its fur, how much it feels good looking into its eyes.  Now the measure is looking for something more positive.  

The old HSP Scale, created back in the 1990s, after interviewing 39 people, describes a trait that has many problems associated with it—for example, needing or preferring to avoid noise, violent TV, chaos, making mistakes, hunger, caffeine, or being under pressure to do a lot.  The items are also mostly negatively worded. I suppose the people I interviewed talked mostly about the problems with being highly sensitive, not the more subtle positive side, such as being more prone than others to notice beauty, feel empathy, or think deeply.  And I did not know enough to focus on that side of the trait.

So, it gave an accurate yet one-sided “advertisement” for high sensitivity.

As for the other problem, the HSP Scale factors, in those days you aimed for a measure that produced one factor—that measured all aspects, showing that if a person answered yes to one, they were likely to answer yes to all the others. The astounding thing to us was that the HSP Scale statistically was one factor.  This was true in spite of the items being so varied–for example, being bothered by pain, easily startled, conscientious, and having a rich inner life. It being one factor suggested that all of these different behaviors were caused by one underlying trait, sensitivity. It was beautiful, really. One factor. 

However, times change in the statistical world, and you now can take a measure like the HSP Scale, with its many varied items, and “force” it to show its underlying factors, even if they are also highly related to each other. In 2004 Smolewska, McCage, and Woody published an important paper on the components of the HSP Scale, naming three factors:  Aesthetic Sensitivity (AES), Low Sensory Threshold (LST), and Ease of Excitation (EOE).  

What Is the Problem with Having Three Sub-Factors?

People began to make extensive use of these three aspects in their research. It seemed as if no one but me had noticed that the factors consisted of one list of positive items, 7 out of the 25 items on the research version of the HSP Scale, and two longer lists of negatively worded items that are honestly difficult to tell apart. Here are the positive ones, all 7, one of the three factors:

Do you have a rich, complex inner life? Do you seem to be aware of subtleties in your environment?Are you deeply moved by the arts or music? Are you conscientious? When people are uncomfortable in a physical environment do you tend to know what needs to be done to make it more comfortable (like changing the lighting or the seating)? Do you notice and enjoy delicate or fine scents, tastes, sounds, works of art? Do you find yourself needing to withdraw during busy days, into bed or into a darkened room or any place?

Even the last item, that could be negative, is positively worded. The name the factor was given, “Aesthetic Sensitivity,”  was clearly a stretch. Conscientiousness?  

Now compare these 7 items to some of the items in the two other factors, which are negatively worded or about negative experiences:  

Some items from the “Ease of Excitation” factor:

Do you tend to be more sensitive to pain? Do you startle easily? Do you get rattled when you have a lot to do in a short amount of time? Are you annoyed when people try to get you to do too many things at once?Do you try hard to avoid making mistakes or forgetting things? 

Some items from the “Low Sensory Threshold” factor:

Are you easily overwhelmed by things like bright lights, strong smells, coarse fabrics, or sirens close by?Are you made uncomfortable by loud noises? Do you make a point to avoid violent movies and TV shows? Do you become unpleasantly aroused when a lot is going on around you?Are you bothered by intense stimuli, like loud noises or chaotic scenes?

Again, these two factors are actually hard to tell apart from their contents. They are simply about the negative side of being highly sensitive.

What Kinds of Problems Are Created by the Old Measure and its Three Sub-factors?

A key issue is what is measured by negatively worded items in general, compared to positively worded items. Given the original one-factor solution, I think it is safe to say that most HSPs experience all three factors—the positive and the negative side of being an HSP. Yet the impression has developed that the three factors represent different types of HSPs, and the ones answering high on Aesthetic Sensitivity (AES) are healthier in some way. But some people, some HSPs even, may answer more negatively worded items than another person for several reasons not directly about related to the items.

An HSP may want to be very honest and accurate, and not shirk the negative.  Indeed, a problem with questionnaires is that people often answer with a positive bias, putting a “rosy glow” on their answers.  HSPs probably do the opposite.They may have a personality that tends to see things more negatively, for whatever reason.  Perhaps they had a difficult childhood.Perhaps they were in a bad mood the day they took the test.Perhaps they are going through a difficult period in their lives.Maybe they are not even HSPs, but have problems going on that could cause them to answer some of these items like an HSP.

Another key problem is the issue of what correlates with these subfactors. Most research with measures looks for a statistical correlation between the score on the measure and something else. Score on a measure of impulsiveness and number of driving tickets.  Score on a measure of athletic interest and number of hours spent each week playing a sport.  A correlation means that when one thing is found, the other is often found.  They are associated.  That is all. But there is an important rule about correlation that even good researchers forget:  Correlation does not mean causation. Impulsiveness does not necessarily cause driving in an manner that gets you driving tickets.  If animals with longer legs run more, it can seem that long legs cause more running. (Or, less logical in this case, that running lengthens your legs.) But goats like to run and have relatively short legs. Lamas have long legs and do not seem to be big runners.  Often a third thing is the cause—breeding within a species to make for faster animals. Fast horses are useful so they have been bred for speed.  Fast goats or cows?  Not so much!

There is a tendency to think, for example, that if a person scores high on the HSP Scale and is often depressed, that being an HSP causes depression. But in fact we know that differential susceptibility is at work here. HSPs with good-enough childhoods are not prone to depression. The third thing is the quality of their childhood. But it turns out that the negatively worded factors of the old HSP Scale correlate more with depression, so it is often implied that people who score high on these factors are the ones who are more depressed.  There is not enough consideration of the five other reasons or “causes” I gave above about why people might score high on these factors.

You can see why creating our own six factors, with a balance of positive and negative factors and items, was necessary.  It not only avoids anyone else finding other, less accurate factors, but solves the “advertisement” problem by giving a complete picture of SPS, as we understand it so far, both positive and negative.  

Some Recent Studies Emphasizing the Three Sub-factors

I do not wish to be negative about these studies. They are just recent examples. There are probably 50 more like them. I just want you to get a sense of the problem.  I wish we had gotten the new measure out years ago, but a good measure takes time.  Meanwhile…

Golonka, K., & Gulla, B. (2021). Individual differences and susceptibility to burnout syndrome: Sensory processing sensitivity and its relation to exhaustion and disengagement.  Frontiers in psychology ,  12 , 751350.

This study of burnout surveyed 516 adult employees, 236 were women and the average age was 29. The sample consisted of employees in IT (26%) and financial businesses, with 10% of the participants in managerial positions.  Most worked full time and had completed higher education.  

Higher scores on the measure of SPS correlated with burnout symptoms, except that higher scores on the AES factor (which they renamed “sensing the subtle”) showed the opposite effect.  They said AES may be a protective factor against burnout.  The question is, what is the causation here, when someone answers higher on AES, with all of its positive items, and also answers that they are not experiencing much burnout.  Does having this wonderful protective factor keep you from developing burn out?  Or does not having burn out make you answer more positively?  Or is a third thing operating.  For example, if you understand you are highly sensitive, perhaps you view the trait more positively and also are able to take better care of yourself and avoid jobs or work situation that lead to burnout.

Iimura, S. (2021). Highly sensitive adolescents: The relationship between weekly life events and weekly socioemotional well‐being.  British Journal of Psychology ,  112 (4), 1103-1129.

This study looked at how 114 Japanese adolescents in Tokyo rated, over four weeks, two of their weekly life events and their well-being that week.  The relation of well-being and sensitivity varied from week to week, sometimes making it look like sensitivity led to lower well-being, and on other weeks like the sensitive adolescents gained more than others from positive experiences, an example of “vantage sensitivity.”  

The main part of the study did not look at the factors, which was good in a way.  But in a footnote the author made the extraordinary observation that when the results were reanalyzed using only the AES subscale, the findings for all weeks supported a strong vantage sensitivity model. Students scoring high on the AES factor were gaining more than students without the trait from their positive experiences.  The question of causation jumps out.  Were students scoring high on AES, the positively worded questions, more prone to seeing everything more positively?  Or were their experiences of the weekly events actually more positive, causing them to answer more items on the AES factor? Or could there be another possibility?  Maybe these sensitive adolescents were experiencing an especially supportive school or home life, so that they could find something good in most of their experiences and also answer more positively-worded items.

Maracineanu, I. G., & Truta, C. (2025). The Relationship between Well-Being and Hypersensitivity among Young Adults.  Bulletin of the Transylvania University of Braşov. Series VII: Social Sciences• Law , 43-52.

These authors looked at the well-being of young adults with “hypersensitivity,” and found that for the most part their well-being was lower. However, this was in fact true only for those high on the two negative factors.  The authors concluded that “People who have difficulty tolerating strong sensory stimuli are more prone to stress and discomfort, which can limit positive experiences.”  

The message is that difficulty with intense stimuli means missing out on positive experiences. But these “people who have difficulty tolerating strong sensory input” are all HSPs, not a separate kind of HSP.  They are probably having at least adequate positive experiences, this being a part of the trait. Yes, being high on the two negative factors was associated with lower well-being, whereas Aesthetic Sensitivity correlated with all of the positive measures in the study: Wellbeing, Positive emotions, Engagement, Good relationships, Finding Meaning in life, Accomplishment, and Happiness.  But of course Aesthetic Sensitivity was also correlated with the overall measure and the two negative factors, Ease of Excitation and Low Sensory Threshold.  That is, as I said before, these are not different groups of people.  Most HSP have all three factors operating and experience some well-being and some negative times–to different degrees, maybe, but we do not have to look for a special subset of HSPs who are miserable due to overstimulation so their positive experiences are limited.  Other issues, third causes, will be limiting their positive experiences, not their difficulty tolerating noise! 

Christou, A. I., Fanti, K., Mavrommatis, I., & Soursou, G. (2025). Parent–Child Eye Gaze Congruency to Emotional Expressions Mediated by Child Aesthetic Sensitivity.  Children .

You can see here the issue with the three factors in the very title of the study.  Children high on Aesthetic Sensitivity behaved differently from other HSCs, but the reasons were barely explored, and certainly not the issue of positive versus negative items.  They were simply the children, some special type of HSC according to the researchers, whom they chose to focus on.

A Few More Points About Measuring SPS

As we expected, while we slowly worked on the new measure and told the world that the old one had some limitations, others made new measures.  A pretty good one is by De Gucht, V., Woestenburg, D. H., & Wilderjans, T. F. (2022). The different faces of (high) sensitivity, toward a more comprehensive measurement instrument. Development and validation of the sensory processing sensitivity questionnaire (SPSQ). Journal of Personality Assessment, 104(6), 784-799. 

This measure aimed to capture more of the positive side of the trait.  But it is very long–43 items  And contains no items on depth of processing (what I consider the foundation of the trait). These are its six factors: Sensory Sensitivity to Subtle Internal and External Stimuli, Emotional and Physiological Reactivity, Sensory Discomfort, Sensory Comfort, Social-Affective Sensitivity, and Aesthetic Sensitivity. 

Another measure, originally in German, was created by Danièle Anne Gubler, Tobias Janelt, Marcus Roth, Katja Schlegel, Jasmin Guggisberg & Stefan Johannes Troche: (2025) The DOES Scale:  Measuring Sensory Processing Sensitivity as a Trait Constellation, Journal of Personality Assessment.

This measure has 20 items divided into the four DOES factors we always talk about. (Depth of processing, easily Overstimulated, strong Emotions/Empathy, and Sensitive to Subtle.) Thus, this measure leaves out what the new HSP-R includes, empathy as something separate from emotion and also positive sensory experiences.

I know there are quite a few other measures that people have made up, compensating for the fact that the old scale had a copyright that did not allow it to be used for anything but clinical or research purposes.  These made-up measures are questionable, of course, not having been validated in research studies.  But hopefully these will fade away. The new measure can be used on anyone’s website if they ask permission from Michael Pluess and print the references at the bottom of the pdf. The pdf is there on my website and on Michael’s, with what must be cited at the bottom. 

So that’s the measuring-SPS saga,  Remember, a questionnaire is not the trait.  Just a bunch of questions!

Part II:  HSPs and the Origin of Religion

Because this first half of my post was SO long, I will keep this “spiritual” half brief.  I thought you would find it interesting that there is a theory that HSPs played a major role in the origin of religion and spirituality. Two experts on the origin of religion, Margaret Rappaport and Christopher Corbally, cite the research on the trait of high sensitivity as support for their theory that the evolution of this trait in humans was a building block in the evolution of religion. In their article “Evolution of Religious Capacity in Genus Homo,” published in 2018 in Zygon (a peer-reviewed journal of science and religion), they suggest that religious feeling evolved out of compassion, and compassion must have three steps:  A certain perception of a situation, sensitivity to its meaning, and then decision making, deciding to act. Think of our six factors—empathy and depth of processing surely lead to compassion. The authors also reason that high sensitivity must have been, and still is, more often present in those who fill religious functions.  

This is all theory, not data, but the reasoning from the evidence satisfied the peer reviewers of the journal. And it makes sense. Another way to frame their ideas is that sensitivity to one’s world inevitably produces the “differential susceptibility” we are always talking about. HSPs are differentially susceptible to the entire world–more deeply affected by both the good events and people and the sad, ignorant, or simply difficult things. It seems that HSPs in particular may have always tended to see better when people were struggling and try to help, to celebrate the good in music and ritual, and to try to figure out where evil comes from.  We wondered why some people cheat, lie, or even murder, what human actions might affect disasters such as droughts or earthquakes, and of course what happens after death.  

Probably we HSPs have always craved to talk about all this, to explore it, while the majority of people gave it less thought. Until, according to these scholars, the rains failed, some tyrant tried to take over, or death came unexpectedly.  Then the majority would want to know what the more thoughtful and kind minority, those HSPs, had to say about it.  What did they think caused evil?  What did they do to avoid bad things happening to them or to manage how they felt afterwards?  Their answers may have been part of the rise of religion.

I’m not sure you need to read their article (actually, it is in three parts).  If you do bring it up using Google Scholar, you can use Control F to search for the word sensitivity.  It will give you a quick sense of how they think about it.  This is the full reference:

Rappaport, M. B., & Corbally, C. (2018). EVOLUTION OF RELIGIOUS CAPACITY IN THE GENUS HOMO: TRAIT COMPLEXITY IN ACTION THROUGH COMPASSION: with Margaret Boone Rappaport and Christopher Corbally,“Evolution of Religious Capacity in the Genus Homo: Origins and Building Blocks”; Margaret Boone Rappaport and Christopher Corbally,“Evolution of Religious Capacity in the Genus Homo: Cognitive Time Sequence”; and Margaret Boone Rappaport and Christopher Corbally,“Evolution of Religious Capacity in the Genus Homo: Trait Complexity in Action through …. Zygon®, 53(1), 198-239.