Over the past few years, there have been a bunch of developments in sensitivity research.

In this episode of The Gentle Rebel Podcast, I share some reflections on the Second International Conference on Sensitivity Research. Michael Pluess, Francesca Lionetti, and Corina Greven oprganised it through The University of Surrey.

In all honesty, academic presentations aren’t really my cup of tea. My mind drifts too easily. But I munched on bananas and persevered because I really think this stuff matters. So I hope this episode helps others who are interested in the essence of sensory processing sensitivity research right now.

Grab a banana, strap in, and explore some of the latest high sensitivity research with me!

The Second Conference on Sensitivity Research

When the train arrived at 1:26 p.m., I knew it would be tight to make the 2 p.m. start. On top of that, the heavens were saturating the world below with rain. All in all, the thirty-minute walk home could have been more appealing. I decided, instead, to hunker down in a café around the corner, and from there, I would watch the International Conference on Sensitivity Research. The event was organised by Michael Pluess, Francesca Lionetti, and Corina Greven through the University of Surrey on Wednesday 22nd May 2024.

Academic presentations aren’t easy for me to follow at the best of times. It takes me many bananas to stay focused, and even then, my brain wanders and falters. Add a busy coffee shop, indulging my love of people-watching, and let’s say I am glad they recorded the conference!

Douglas Adams said, “If you really want to understand something, the best way is to try and explain it to someone else.”

Well, I do want to understand this stuff, so I’m embarking on what currently feels like an impossible challenge… I will attempt weaving together what I understood of the research and explain it to the best of my ability. Please note that I do this in a spirit of humility. I invite you to clarify, contradict, and correct any misunderstandings.

No Cut-Offs

Before I get into the conference content, I want to share these three words.

“No cut-offs” was the collective agreement among the panel at the end of the conference.

Despite my initial assumption, it wasn’t fashion advice. They weren’t attempting to disuade attendees from repurposing old jeans by chopping them into denim shorts for the summer.

Instead, “no cut-offs” referred to how we measure and talk about high sensitivity in individuals. Because sensitivity is complex and on a continuum, it is difficult to definitively measure and label a tipping point when someone becomes a Highly Sensitive Person (HSP). So when I refer to HSPs in this post, it’s a description of those who score higher on the sensitivity scales.

During the conference, we heard from researchers who have built on the existing foundations to better understand the nature, purpose, and characteristics of sensitivity. The studies examine Sensory Processing Sensitivity (SPS) in different contexts and under various environmental and cultural conditions. They also show new scales for observing, measuring, and assessing factors associated with sensory processing sensitivity.

I am personally interested in how the research can help us design, create, and maintain favourable spaces and routines for more sensitive people. And how we can support those working with HSPs with a better practical understanding of the associated traits. I also want to explore how we might nurture and amplify the voice of high sensitivity as part of our collective survival strategy.

Getting Started

As it turned out, I could have made it home and still had time to put the kettle on before the conference. It started in beautiful chaos. Oh, don’t you just love technology! We joined the Teams meeting and watched as Art Aron tried unsuccessfully to get the sound working on his end. I’m sure everyone in the group felt an empathetic surge of mildly flustered panic.

Michael Pluess remained cool (on the outside, at least) and calmly invited the crowd of 200+ attendees to relocate to Zoom. He kept a wonderfully peaceful presence even though he must have tasted a little stress beneath the surface. He’s one of those people that naturally gives you the feeling that you’re in safe hands.

30 Years of Sensitivity Research and Collaboration

Once the technology agreed to play ball, Art and Elaine Aron began the conference by highlighting some of their collaborators from the past three decades, notably a sensitive Pumpkin-Seed Sunfish. Surprising!

They picked out some favourite sensitivity research through the years, including one showing how highly sensitive people are naturally less affected by cultural biases in their perception of stimuli. Whether a person’s culture values the individual or the collective more highly impacts HOW individuals process and perceive data. It turns out that because of the deeper processing, HSPs can perceive ideas, people, and situations more objectively than less sensitive individuals.

Elaine celebrated that, while for better or worse, environmental conditions have a greater influence on a sensitive nervous system, a highly sensitive person’s perception is less naturally swayed by the values and beliefs in the culture around them.

This area interests me because it speaks to the value of high sensitivity in the collective context. Might it also mean that HSPs are less likely to get swept up in group-think and more likely to quietly question mob-minded assumptions? What could the upshot of that be for the voice of sensitivity more broadly? I’d be interested in learning about any research that follows this thread to see if there is a link.

The Arons trotted through a few research headlines to give us a flavour of recent work. HSPs have been found to demonstrate higher emotional responsiveness to positive and negative images and can perceive emotions in other people more easily. Highly sensitive people are equally likely to be sensation seekers as the general population. And they’ve noticed a link between sensitivity to medications and the trait of SPS.

Continued Confusion Surrounding High Sensitivity

Elaine also discussed a study currently under review exploring the reasons for continued confusion surrounding the trait of high sensitivity. This is noteworthy because it will provide an opportunity to reevaluate and revise many of the assumptions that have become ingrained in popular discussions over the years.

One of the reasons the trait sometimes receives criticism is the abundance of information disseminated through online popular culture, which often portrays an incomplete or even incorrect picture of what we know to be true. However, she also notes a palpable shift towards accepting and understanding the evidence, firmly establishing high sensitivity as a natural trait and not just a subject for popular self-help books.

Other potential reasons for confusion include misconceptions about extroverted and high sensation-seeking behaviour, both of which remain common for HSPs. Additionally, most typical HSPs are less visible because they go about their lives without realising they are highly sensitive. Furthermore, while half of HSPs are men, they tend to be less visible, whether by choice or a lack of awareness.

There are also inherent difficulties in observing the depth of processing, which is at the trait’s core. For example, it’s hard to spot people (and ourselves) pausing to notice before acting. The original HSP Scale misses essential aspects and underestimates the importance of depth of processing. HSPs also differ widely because of differential susceptibility (positive and negative environmental effects on sensitive individuals), sprinkling confusion on our expectations for how a highly sensitive person ought to sound, look, and act.

Highly Sensitive Children in the School Context

Jenni Kähkönen from Queen Mary University of London started the research presentations with her study into highly sensitive children. This centred on teacher-reported sensitivity collected through a newly developed Highly Sensitive Child in School Scale.

Core Sensitivity On The Highly Sensitive Child in School Scale:

• a child easily noticing how others are feeling
  
• thinking deeply about things
  
• being very sensitive to injustice
  
• getting easily distressed when other children are fighting
  
• appearing to feel things deeply
  
• trying hard to avoid making mistakes or forgetting things
  

These were consistent factors across Swiss and UK children and were identified equally in girls and boys.

They found a link between the Overstimulation and Core Sensitivity scales in the UK but not Switzerland.

Overstimulation is indicated by:

• a child struggling to focus in loud and chaotic situations
  
• needing quiet time after an exciting activity
  
• feeling easily overwhelmed when under pressure
  

If a school environment is very good, the child might not display overstimulated behaviours. This may indicate that the environment is inherently calming to the child. Or it might mean the child waits to feel safe before displaying behaviours linked to overstimulation, i.e., once they get home at the end of the day.

Several other differences existed between the two schools. In the Swiss study, the teacher-reported sensitivity predicted higher social competence and grades. This was not the case in the UK, where there was no correlation between sensitivity and higher social competence or grades.

There was a link to predicting signs of worry for sensitive children in the UK, unlike in Switzerland, where no such internalising symptoms were identified.

Higher sensitivity predicted lower externalising symptoms (attention issues, hyperactivity, and conduct problems) in both countries.

Environmental Conditions and Sensory Sensitivity

The research supports the notion that more sensitive children can benefit from calmer working environments and quiet time to recharge after exciting activities. Teachers should be mindful that social or time-pressured tasks may impact more sensitive children. But sensitive children can succeed when conditions are favourable. It is worth considering the impact of class size and classroom design in enabling more sensitive children to thrive.

High Sensory Processing Sensitivity: Blessing or Challenge?

Veronique de Gucht, from Leiden University explored whether high sensitivity might be considered a blessing or a challenge. She shared findings from studies into sensitivity, giftedness, and resilience.

6 Scales of Sensory Processing Sensitivity

Veronique introduced the new Sensory Processing Sensitivity Questionnaire (SPSQ), an updated tool for understanding and measuring sensitive traits. The questionnaire covers six sensitivity categories and offers a more nuanced and comprehensive approach to sensitivity research.

Negative Dimension of Sensitivity

• sensory discomfort
  
• emotional and physiological reactivity
  

The study found those who score more highly for the two scales on the negative dimension, are more likely to experience physical or psychological symptoms like fatigue, physical complaints, depression, and anxiety.

Positive Dimension of Sensitivity

• sensory sensitivity
  
• sensory comfort
  
• social-affective sensitivity
  
• aesthetic sensitivity
  

There was a much lower link between those same symptoms and higher scores on the positive dimension.

Using the two dimensions of sensitivity feels like a helpful step forward. It should allow us to see the impact of different sensitivity scales across various contexts.

Giftedness and High Sensitivity

Veronique shared a study examining the link between giftedness and SPS. It found that gifted individuals scored lower on the Negative Dimension Scales than the general population. There was no real difference on the Positive Dimension.  There is nothing in these findings to suggest sensory processing sensitivity makes an individual more likely to be gifted or that gifted people are more likely to have the SPS trait.

A follow-up study explored whether resilience reduces the adverse effects of heightened sensitivity. It found that higher scores for the negative aspects of sensitivity correlate with lower resilience and higher symptoms. Whereas, higher scores for the positive dimension scales correlate with greater resilience and lower symptoms.

This suggests that resilience has the potential to alleviate the negative impact of SPS on an individual. This is crucial for practitioners to consider when working with sensitive people.

Interventions (therapy, coaching, training etc), can help HSPs cope with the negative aspects of sensitivity (sensory discomfort and emotional and physiological reactivity). But support can also enhance the positive aspects of sensitivity. This can help the individual align with their environment and thrive on their own terms.

Genetics of Environmental Sensitivity and its Association with Mental Health and Wellbeing

Dr. Elham Assary from King’s College London gave the third presentation. Her research delved into how high sensitivity relates to mental well-being. She then explored whether genetic or environmental factors correlate with greater depression, anxiety, and autistic traits in Highly Sensitive People.

The study measured subjective well-being using questionnaires and self-reports to create a comprehensive picture of personal well-being. It found that more highly sensitive individuals reported feeling less hopeful, less optimistic, and less happy (subjective well-being). There no significant difference in curiosity, gratitude, ambition, and grit (psychological well-being).

This suggests that while HSPs may experience psychological well-being, they might still FEEL dissatisfied or unhappy with their life.

A Link Between Aesthetic Sensitivity and Psychological Wellbeing

The results highlighted a curious link between high aesthetic sensitivity and increased psychological well-being. Aesthetic sensitivity refers to the ability to perceive and appreciate beauty through the senses, such as being deeply moved by art, music, nature, flavours, and scents.

We might connect the dots with the previous research and question whether our relationship with art and beauty can help build resilience and mitigate the adverse effects of sensitivity. It would be fascinating to explore if and how we might be able to deepen our aesthetic sensitivity to increase psychological well-being.

The twin study also revealed that sensitivity and mental health outcomes are primarily influenced by shared genetic factors rather than environmental ones. This means that the same genetic traits leading to high sensitivity also predispose individuals to depression, anxiety, and autistic traits. However, despite a correlation, nothing indicates a causal relationship.

Dr. Assary suggested that a better understanding of the genetic basis of sensitivity could help identify predispositions to anxiety, depression, and autistic traits, enabling more targeted interventions. We might also consider what underpins our subjective judgement of well-being (feeling less happy, satisfied, hopeful, etc) and whether that is a story that we can shift in time.

Sensitivity and Overstimulation

I think there was then a short break in the presentations at this point. But it must have been brief because the next session had already begun when I returned from the toilet ordering more bananas.

We then had three five-minute flash talks. The first was delivered by Dr Sofie Weyn, who looked at HSP overstimulation and how it fluctuates during the day and across different contexts.

The diary study got participants to gauge and record levels of overstimulation, environment, moods, fatigue, and pleasantness of stimuli in the environment (sounds, sights, smells, tastes, touches) throughout the day.

Sofie found that overstimulation fluctuated throughout the day for everyone regardless of sensitivity, with the highest levels between 5 and 6 p.m. Overstimulation decreased later in the evening. There was an increase across the board in public spaces, especially when other people, negative moods, and fatigue were reported. Overstimulation also increased with reports of unpleasant sounds, lights, smells, tastes, and touches.

Overstimulation was significantly higher for highly sensitive individuals when their fatigue level rose. However, overstimulation decreased when they reported higher levels of pleasant sounds, visual stimuli, and positive moods. This shift was much more prevalent for more sensitive than less sensitive individuals, consistent with the theory that HSPs are more significantly impacted by positive and negative environmental stimuli.

These findings reinforce the need for awareness of variations in overstimulation and to work WITH those fluctuations rather than fighting against them. Focusing on rest and sleep quality can mitigate fatigue, increasing pleasant auditory and visual stimuli through music and ambient lighting in environments we can control and noise-cancelling headphones, dampened lighting, or tinted glasses in conditions we can’t change.

Attentional Capture and Sensitivity

Robert Marhenke from the University of Innsbruck gave the second flash talk about Attentional Capture and Sensitivity. He introduced the concept of selective attention, which has been assumed to be lower in highly sensitive people. Why? Because, as we know, highly sensitive people process information more deeply, are more aware of subtle stimuli, are more easily overwhelmed and distracted by extraneous stimuli, and have a lower ability to filter out irrelevant information.

He explored this through two theories of attentional capture: the Bottom-Up Theory, where our attention is drawn to a stimulus based on its properties (e.g., bright colours or distinctive characteristics), and the Top-Down Theory, where our attention is directed by preconceived intentions, goals, or knowledge (e.g., something we know we want to find).

The study found that individuals high in SPS were not more easily distracted by striking elements in the Bottom-Up experiment. Results from the Top-Down experiment found that highly sensitive individuals were less biased by their own intentions and goals, so they were, in fact, better at ignoring distractions, even if they were similar to what they were looking for.

It might be surprising that HSPs are not more easily distracted by environmental stimuli. However, this aligns with the study Elaine and Art Aron highlighted, showing that cultural influences on perception impact sensitive individuals. So, even though HSPs are more affected by their environment, this doesn’t inhibit their ability to process and perceive it with a greater sense of objective discernment. Interesting!

Effects of Sensitivity and Childhood Family Conflict on Objective Stress Responding

Sophia Bibb then delivered her inaugural research talk as a first-year PhD student at Ohio State University. She shared her research into the Effects of Sensitivity and Childhood Family Conflict on Objective Stress Responding. Despite mixed results in recent studies, this was based on the previous assumption that stress affects highly sensitive people more than less sensitive individuals.

Sophia looked at the effect of different stress types on sensitive individuals. Predictable threats elicit a fear response (a time-locked reaction to a tangible stressor), and unpredictable threats cause anxiety (an anticipatory state of chronic arousal).

The research examined the relationship between SPS, childhood family conflict, and objective stress response. It found a correlation between high family conflict in childhood and increased reactivity to unpredictable threats later in life. However, it showed no relationship between SPS and reactivity to unpredictable threats for those who didn’t experience family conflict growing up. This suggests that SPS alone doesn’t equate to greater anxiety. Interestingly, individuals low in SPS who experienced family conflict showed lower reactivity to unpredictable threats than those who hadn’t.

Sophia concluded from this research that HSPs are not inherently more biologically reactive to stress. Also, HSPs may experience greater sensitisation to childhood stress, particularly to sustained, unpredictable stressors. This is consistent with the Diathesis-Stress Component, which indicates that greater reactivity in a sensitive individual is contingent on early sensitisation events like high family conflict. Understanding the interaction between SPS and biological stress reactivity can inform approaches to psychopathology and interventions for HSPs.

Measurements of Sensitivity

The three-hour conference concluded with a panel discussion about measuring sensitivity. I’ll admit, by this point in the live event, my brain was frazzled, and I couldn’t process anything. I was beyond the banana, so I was grateful to have a recording to go back and watch later.

The panel explored the strengths and limitations of how sensitivity is currently observed, measured, and applied in research and practice.

Elaine Aron reiterated the centrality of depth of processing to high sensitivity and how challenging it can be to observe and measure. Veronique de Gucht pointed out that very few people would choose to answer a question in a way that sounds like they have no depth. In such a case, respondents are likelier to answer questions based on what is socially desirable rather than true.

The Negative Effects of High Sensitivity

Elaine laments the negative flavour of the original HSP Scale, which was developed through exploratory processes rather than being built on the foundations of an initial theory with well-established definitions. If she could go back and start again with the initial scale, she would emphasise the depth of processing more and focus less on overstimulation. But I would love her to cut herself some slack because she seemed pretty hard on herself about the whole thing. They did what they could with what they had at the time, and sensory processing sensitivity was a completely new, unexplored field to uncover and discover. This is how these things start and evolve. Imperfectly and in ways we later regret with the benefit of hindsight!

The six new scales provide a richer and more detailed understanding of different elements of sensitivity. They are emotional and physiological reactivity, sensory sensitivity, sensory comfort, sensory discomfort, social-affective sensitivity, and aesthetic sensitivity. These scales provide greater potential flexibility to future research and are already being integrated into collaborations with other fields of study unrelated to high sensitivity.

The panel also discussed the need for specialised training to understand the functional diagnosis of sensory processing sensitivity. In other words, we need to move away from what I heard described as “differential diagnosis,” which I believe means categorising high sensitivity as dysfunction (comparable to normative functioning) rather than a core biological function of an individual. This requires knowledge and acceptance of the core sensitivity traits in humans.

No Cut Offs

OK, I think we are there. So, let’s finish where we started and return to those three words, “no cut-offs” (I’m still not talking about denim shorts). While many individuals, as well as teachers and parents, might seek definitive answers (is this child HSP or not?), it’s not possible or even desirable to treat sensitivity in this way. Environmental factors complicate it, and careful consideration is needed regarding the potential harm an individual might face if the HSP label is labelled and used about them.

I felt heartened by this conference, especially after watching it back (several times) and starting to grasp what was being communicated. I hope we might see an increasing flow of discoveries related to sensory processing sensitivity across disciplines, fields, and backgrounds.

There are many elements I would love to explore, so I look forward to finding out where the research goes next. I still get most excited when highly sensitive people see themselves reflected in descriptions of the trait so they can begin the journey of growth in self-understanding, acceptance, and awareness and explore who they’ve always been in light of their sensitivity, not in opposition to it.

Watch The Video of My “Summary”

https://www.youtube.com/watch?v=FkGsvdA3htw&