What is an HSP? The Highly Sensitive Person and the Neurodiversity Spectrum
Thursday, February 6, 2025.This is for Viv in Vancouver.
We seem to be living in an age in which resilience is championed and emotional toughness is often equated with success.
In such world, high sensitivity can feel like a liability.
But for an estimated 15–20% of the population, sensitivity is not just a temperament—it’s a neurobiological reality (Aron, 1997).
These folks, known as Highly Sensitive Persons (HSPs), experience the world more intensely than their peers, processing sensory input, emotions, and social cues at a much deeper level.
But what exactly makes an HSP different?
Is high sensitivity a disorder, an advantage, or simply a variation of normal human neurobiology? And how does this trait intersect with other forms of neurodiversity, such as autism, ADHD, and giftedness?
This post will take a deep, research-backed dive into the world of HSPs, exploring their biological underpinnings, their connection to other forms of neurodivergence, the challenges they face, and the ways they can harness their unique strengths to thrive.
The Science of High Sensitivity: A Deeply Wired Brain
The term Highly Sensitive Person was coined by psychologist Dr. Elaine Aron in the 1990s to describe those with a genetic trait called Sensory Processing Sensitivity (SPS) (Aron, 1997). This trait is not a disorder—it is a heritable neurological characteristic found in roughly 20% of humans and more than 100 species of animals (Wolf et al., 2008).
Neuroscience and HSPs: How Their Brains Are Different
Studies using functional magnetic resonance imaging (fMRI) have revealed that HSPs show greater activation in brain regions associated with sensory processing, emotional regulation, and empathy (Acevedo et al., 2014). These include:
The Insula – Responsible for interoception (awareness of internal bodily states) and emotional awareness. HSPs have heightened insula activity, which may explain their deep self-awareness but also their tendency toward anxiety and emotional overwhelm.
The Anterior Cingulate Cortex (ACC) – This region processes decision-making and emotional conflict resolution. High activation in HSPs suggests they evaluate choices deeply, making them cautious but also prone to overthinking.
The Mirror Neuron System – HSPs exhibit stronger mirror neuron responses, indicating an intensified ability to pick up on others’ emotions (Acevedo et al., 2014). This explains why HSPs often absorb the moods of people around them—for better or worse.
Interestingly, HSPs process sensory data with heightened granularity, meaning they notice more details in their environment, from subtle changes in facial expressions to background noises others filter out.
HSPs and the Neurodiversity Spectrum
HSPs are not the only folks who experience heightened sensory and emotional responses.
Many traits of high sensitivity overlap with autism, ADHD, and giftedness. However, these are distinct neurocognitive profiles, each with unique strengths and challenges.
HSP vs. Autism Spectrum Disorder (ASD)
There is significant overlap between HSPs and autistic folks, particularly in sensory processing and depth of perception. However, there are key differences:
Sensory Sensitivity: Both HSPs and autistic people experience strong sensory reactions, but autistic folks often struggle with sensory integration, leading to meltdowns or shutdowns in overwhelming situations (Liss et al., 2008). HSPs, on the other hand, tend to emotionally regulate more effectively (unless highly stressed).
Social Cognition: HSPs have enhanced social intuition and can read nonverbal cues with extreme accuracy. Many autistic folks, in contrast, experience challenges in interpreting social cues (Baron-Cohen, 2009).
Cognitive Processing: Autistic folks often engage in pattern-based thinking and intense special interests, while HSPs tend to process emotions and interpersonal dynamics deeply.
Some researchers suggest that certain autistic folks may also be HSPs, but not all HSPs are autistic (Liss et al., 2008). The two share sensory sensitivity, but HSPs do not typically experience the social communication difficulties associated with ASD.
HSP vs. ADHD: Sensitivity Meets Impulsivity
At first glance, HSPs and souls with ADHD seem opposite—one is highly reflective and deliberate, while the other is impulsive and distracted. However, some individuals exhibit traits of both (Aron, 2010).
Overstimulation: Both HSPs and ADHDers struggle with overstimulation, but for different reasons—HSPs due to deep sensory processing, ADHDers due to difficulty filtering distractions.
Dopamine and Attention: ADHD is linked to dopaminergic dysfunction, making them seek high-stimulation environments (Volkow et al., 2011). HSPs, on the other hand, withdraw from excessive stimulationto regulate their nervous system.
Emotional Reactivity: Both ADHDers and HSPs can be emotionally intense, but ADHDers often have difficulty regulating emotions, while HSPs tend to deeply analyze emotions and ruminate.
Interestingly, some people with ADHD also identify as HSPs, which suggests to me that high sensitivity may be an under-recognized trait within the ADHD community.
HSP vs. Giftedness: The Intersection of Depth and Intellect
Many gifted folks display traits that mirror HSP characteristics, particularly in emotional intensity, deep processing, and heightened perception.
Dabrowski’s Overexcitabilities: Polish psychologist Kazimierz Dabrowski identified "overexcitabilities" in gifted folks, including emotional, sensory, and intellectual intensities (Dabrowski, 1972). These are strikingly similar to HSP traits.
Deep Thinking: Gifted people analyze and reflect deeply, much like HSPs. However, HSPs are more emotionally focused, while gifted folks tend to be cognitively analytical.
Not All Gifted People Are HSPs: While many gifted souls exhibit heightened sensitivity, not all gifted people fit the emotional depth and empathy profile of HSPs (Silverman, 2013).
HSP Strengths: The Hidden Superpowers of Sensitivity
Despite the challenges of high sensitivity, HSPs possess extraordinary strengths, including:
Emotional Intelligence: HSPs are often deeply intuitive and empathetic, making them natural therapists, teachers, artists, and caregivers.
Creative Depth: Many renowned writers, musicians, and thinkers are HSPs, leveraging their depth of perception to produce profound work.
Strong Moral Compass: HSPs are deeply conscientious, often acting as moral anchors in families and communities.
Enhanced Problem-Solving: Because HSPs analyze situations deeply, they foresee problems others miss, making them highly valuable in leadership roles that require foresight and emotional intelligence.
Sensitivity is a Gift, Not a Weakness
For too long, sensitivity has been misunderstood as a flaw rather than a legitimate neurobiological trait.
However, as research continues to reveal, HSPs are an essential part of the neurodiverse spectrum, bringing depth, creativity, and insight to a world that often prioritizes speed over reflection.
Rather than asking, “Why am I so sensitive?”, perhaps the real question should be:
“How can I honor my sensitivity as a strength?”
Be Well, Stay Kind, and Godspeed.
REFERENCES:
Acevedo, B. P., Aron, E. N., Aron, A., et al. (2014). The highly sensitive brain: An fMRI study of sensory processing sensitivity. Brain and Behavior, 4(4), 580–594.
Aron, E. N. (1997). The Highly Sensitive Person. Broadway Books.
Baron-Cohen, S. (2009). The Essential Difference: Male and Female Brains and the Truth About Autism. Basic Books.
Dabrowski, K. (1972). Psychoneurosis Is Not an Illness. Gryf Publications.
Liss, M., et al. (2008). Sensory processing sensitivity and autism. Personality and Individual Differences, 45(3), 255–259.