The conceptual framework of neurodiversity has fundamentally shifted how we view variations in human brain function, moving away from a pathology-focused model toward one that recognizes a natural spectrum of cognitive and neurological types. Within this landscape, the Highly Sensitive Person (HSP), characterized by the personality trait of sensory processing sensitivity (SPS), occupies a complex and often debated space. While SPS is officially categorized as a temperament variation rather than a neurodevelopmental disorder, many individuals and clinicians are beginning to question whether the distinction between high sensitivity and neurodivergence is as clear as once thought. The primary question is not merely one of semantics, but rather whether the neurological foundations of SPS warrant its inclusion under the neurodivergent umbrella.
Sensory processing sensitivity is defined by a greater depth of information processing, increased emotional reactivity, and a lower threshold for sensory stimuli (Aron & Aron, 1997). Researchers have long argued that this trait is distinct from clinical conditions like Autism Spectrum Disorder (ASD) or Attention-Deficit/Hyperactivity Disorder (ADHD), noting that while there is overlap in sensory hyper-reactivity, SPS does not inherently include the social communication challenges or executive functioning deficits central to those diagnoses (Acevedo et al., 2018). Neuroimaging studies have supported this distinction by showing that when individuals with high SPS process social stimuli, they exhibit increased activation in brain regions associated with empathy, awareness, and self-other processing, such as the insula and the cingulate cortex (Acevedo et al., 2014). This contrasts with some patterns seen in autism research, where social-emotional processing may involve different neural pathways or degrees of activation.
However, the definition of neurodivergence itself has expanded beyond its original diagnostic boundaries to include any brain that functions differently from what is considered the societal norm. If we accept the neurodiversity paradigm, the fact that high sensitivity is a biologically based, heritable trait that affects approximately twenty percent of the population suggests it is a legitimate neurotype (Aron, 2013). Recent studies have identified a significant correlation between high SPS scores and self-reported traits of ADHD, suggesting that the sensory gating mechanisms—the brain’s ability to filter out redundant or unnecessary stimuli—may function similarly in both highly sensitive and neurodivergent individuals (Panagiotidi et al., 2020). This shared physiological experience of a “porous” filter suggests that the boundary between a temperament trait and a neurodevelopmental difference may be more fluid than current diagnostic manuals suggest.
The debate is further complicated by the reality of misdiagnosis and masking. Many individuals who identify as HSPs may actually be undiagnosed autistic people or have ADHD, particularly those who have learned to mask their social or executive difficulties to fit into neurotypical environments. Research indicates that a large percentage of people identifying as highly sensitive also report signs commonly associated with autism, such as a deep need for predictability and a high degree of specialized knowledge in specific interests (Bjelland, 2024). In these cases, the label of HSP can act as a more socially palatable or accessible entry point for understanding one’s neurobiology, even if it does not capture the full scope of their neurodivergent experience.
Ultimately, whether we formally classify high sensitivity as neurodivergence depends on whether we prioritize diagnostic categories or lived experience. If neurodivergence is defined by a nervous system that processes the world with a higher degree of intensity and depth than the majority, then the highly sensitive brain undoubtedly fits the description. Recognizing SPS as part of the neurodiversity spectrum does not necessarily mean pathologizing it; instead, it allows for a more nuanced approach to support and accommodation. Just as we have learned to adapt environments for those with ADHD or autism, recognizing the specific needs of the highly sensitive nervous system—such as the requirement for lower stimulation and more frequent downtime—is a necessary step in fostering a more inclusive understanding of the human mind.
References
Acevedo, B. P., Aron, E. N., Aron, A., Sangster, M. D., Collins, N., & Brown, L. L. (2014). The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others’ emotions. Brain and Behavior, 4(4), 580–594.
Acevedo, B. P., Jagiellowicz, J., Aron, E. N., Marhenke, R., & Aron, A. (2018). Sensory processing sensitivity and childhood adversity: Differential effects on neural response to emotional cues. Social Cognitive and Affective Neuroscience, 13(12), 1313–1323.
Aron, E. N. (2013). The highly sensitive person. Kensington Publishing Corp.
Aron, E. N., & Aron, A. (1997). Sensory-processing sensitivity and its relation to introversion and emotionality. Journal of Personality and Social Psychology, 73(2), 345–368.
Bjelland, J. (2024). Research: HSPs and autism. Sensitive and Neurodivergent Education.
Panagiotidi, M., Overton, P. G., & Stafford, T. (2020). The relationship between sensory processing sensitivity and attention deficit hyperactivity disorder traits. Individual Differences Research, 18(1).
