Do you get headaches from a colleague’s strong perfume? Does the glare from the phone screen of the person next to you on the train feel like an assault on your eyes? After a long day or a loud event, do you crave absolute silence and solitude to recharge? If you answered yes, you might have heard the term Highly Sensitive Person (HSP). It's said that about 15-20% of the population fits this description, possessing a nervous system that processes the world with greater intensity and subtlety. But let's be honest, we can all get overwhelmed by strong smells or loud music. Does that mean we're all highly sensitive? While the term has gained immense popularity, it's worth asking: Is this a genuine, innate trait? Or could there be something else behind these powerful reactions to the world around us?

A New Age of Awareness

It might feel like people who are acutely sensitive to their surroundings are a recent phenomenon. Five years ago, it seems fewer people complained about sensory overload from background music in a café or a draft on the bus. Now, it appears there's an army of sensitive individuals, and their voices are amplified by our interconnected world. So, where did all these people come from? The truth is, they’ve always been here. What's changed is society. We've grown more humane, more considerate of others' sensitivities. In the past, a group wouldn't typically adjust its behavior for one person's comfort. The prevailing attitude was that if everyone else was fine, the outlier should simply toughen up. Today, there's a growing understanding that individuality and personal boundaries matter. Setting those boundaries is no longer seen as embarrassing. It's perfectly acceptable to say, “No, I can't go to that shop; the smells give me a headache.” We're beginning to accept that sensitivity isn't an abnormality but a spectrum.

Is It Sensitivity, or Is It Stress?

Our level of sensitivity isn't static; it fluctuates based on our internal state. Imagine you've had a poor night's sleep, skipped breakfast, and arrived at work to face a mountain of urgent tasks. Even the slight creak of your office chair can feel like a major irritant. Your brain, already taxed by trying to find a sense of safety and meet basic needs, perceives every additional stimulus as a threat. In that moment, a friendly colleague popping by to ask how you are—a normally pleasant interaction—can feel grating. It's not them; it's the context. When our biological needs go unmet or when we're under chronic stress, our bodies enter a constant state of defense. Our sensitivity spikes, making it difficult to regulate our emotions and reactions. It's a natural survival mechanism, not a personality flaw.

Deconstructing the HSP Theory

The term "Highly Sensitive Person" was popularized in the 1990s by psychologist Elaine Aron. According to her theory, HSPs are defined by four key traits, often summarized by the acronym D.O.E.S.:

• Depth of processing: They think deeply about things and process information more thoroughly.
• Overstimulation: They are easily overwhelmed by sensory input like bright lights, loud noises, or chaotic environments.
• Emotional reactivity and Empathy: They experience emotions—both positive and negative—more intensely and have a strong sense of empathy for others.
• Sensing the subtle: They notice small details in their environment that others might miss.

Aron proposed that this is an innate, biological trait, possibly linked to genes like the 5-HTTLPR gene, which is involved in serotonin transport and mood regulation. However, this is where the theory's scientific foundation begins to look shaky. That same gene is also linked to a variety of neuropsychiatric conditions, including depression. There's simply not enough conclusive, large-scale research to definitively tie specific genes to the HSP trait as a distinct phenomenon. The evidence remains weak.

The Uncomfortable Overlap: Autism and Sensory Processing

The most significant criticism of the HSP concept is its profound overlap with the characteristics of Autism Spectrum Disorder (ASD), particularly what was once called Sensory Processing Disorder. Many of the core experiences described by self-identified HSPs—such as social exhaustion and sensory overload—are also hallmark features of autism.

Let's look at the parallels:

• Social Exhaustion: An HSP might feel drained after a day of meetings and need quiet time to recover. Similarly, for a person with autism, social interaction requires immense mental effort, often because they are consciously "masking" their autistic traits to fit in with neurotypical expectations. This can lead to exhaustion or even an emotional meltdown.
• Sensory Overload: An itchy sweater tag, bright fluorescent lights, or the low hum of a refrigerator can be intensely irritating or even painful for someone with heightened sensory sensitivity. While HSP proponents often discuss this, research has confirmed that sensory features are a core component of the autism spectrum.

A common argument used to differentiate HSP from ASD is that HSPs possess strong empathy, while people with autism supposedly do not. This is a harmful and outdated stereotype. Difficulties in reading social cues, understanding irony, or intuitively grasping unwritten social rules are not an absence of empathy. Many autistic individuals experience profound affective empathy—the ability to feel what others are feeling—sometimes to an overwhelming degree. The myth of the emotionless autistic person has long been debunked in clinical science, yet it persists in popular culture.

The Danger of a Convenient Label

If the symptoms are so similar, why do we need a separate, non-clinical term like HSP? For many, the label "highly sensitive" feels more acceptable and less stigmatizing than a clinical diagnosis like ASD. It offers an explanation for feeling different, for being the person who gets exhausted by parties or annoyed by a friend chatting loudly on the phone. The desire to understand oneself is natural and healthy. However, creating a new, scientifically unproven label risks complicating the diagnostic process and reinforcing harmful stereotypes. It can prevent individuals from seeking a proper evaluation and accessing support that could genuinely help them navigate the world. We've seen this before with vague, catch-all diagnoses that obscure the real underlying issue. The goal here isn't to invalidate anyone's experience but to encourage a healthy skepticism and a deeper, more critical look at the labels we use. Is "highly sensitive person" a useful descriptor for a common human experience, or is it a comforting veil for something that we, as a society, are still learning to understand and accept without judgment? Perhaps by questioning the label, we can move closer to a more nuanced and accurate understanding of neurodiversity in all its forms.

References

• Aron, E. N. (1996). The Highly Sensitive Person: How to Thrive When the World Overwhelms You. Citadel Press.
  This foundational book by Elaine Aron introduces the concept of the Highly Sensitive Person (HSP). It outlines her theory based on the D.O.E.S. model (Depth of processing, Overstimulation, Emotional reactivity/Empathy, Sensing the subtle) and provides self-tests and coping strategies for individuals who identify with the trait. It serves as the primary source for understanding the HSP concept as it was originally popularized.
• Ben-Sasson, A., Hen, L., Fluss, R., Cermak, S. A., Engel-Yeger, B., & Gal, E. (2009). A meta-analysis of sensory modulation symptoms in individuals with autism spectrum disorder. Journal of Autism and Developmental Disorders, 39(1), 1–11.
  This major meta-analysis synthesizes data from numerous studies to confirm that sensory processing issues are a core and prevalent feature of Autism Spectrum Disorder (ASD). The findings provide strong scientific evidence that heightened sensitivity and unusual sensory responses, key traits often attributed to HSPs, are integral to the clinical description of autism.
• Acevedo, B. P. (2020). The basics of sensory processing sensitivity. In B. P. Acevedo (Ed.), The Highly Sensitive Brain (pp. 1-18). Academic Press.
  This chapter explores the neurobiological underpinnings of Sensory Processing Sensitivity (SPS), the scientific term for the HSP trait. Acevedo discusses brain imaging studies showing that individuals with high SPS have more active neural circuits related to awareness, empathy, and self-other processing, arguing for SPS as a distinct biological trait while also acknowledging its symptomatic overlap with other conditions.