The Highly Sensitive Person: A Research-Based Overview for Practitioners

As coaches and therapists, we work with a wide range of clients, many of whom may present with traits that are difficult to categorise within more conventional frameworks. They might describe feeling chronically overwhelmed, emotionally exhausted, or fundamentally different from the people around them. For a significant proportion of these clients, what we are actually looking at is sensory processing sensitivity, more commonly known as the highly sensitive person trait. Understanding the research behind this can meaningfully shape how we support them.

What Is the Highly Sensitive Person Trait?

The concept of the highly sensitive person was developed by Dr Elaine Aron, whose research identified that approximately 20% of the population carries specific genetic markers that cause the brain and nervous system to process information differently. This is not a disorder, a diagnosis, or a pathology, but an innate trait.

The formal term used in the research literature is sensory processing sensitivity, and one of the most compelling aspects of this work is that the trait has been identified in over a hundred other species. This tells us something significant: sensory processing sensitivity is not an anomaly but it’s an evolutionary strategy.

An Evolutionary Perspective

To understand why high sensitivity exists at all, it helps to look at it through an evolutionary lens. In earlier human communities, not everyone needed the same set of traits and capabilities. There were those who were bold, decisive and action-oriented, and then there were others who were more observant, deeply attuned to their environment, and highly perceptive of both threats and opportunities. The healers, the caregivers, the ones who noticed subtle shifts in the natural world or in the emotional climate of the group. These individuals would have offered an enormous survival advantage to their communities precisely because of their sensitivity.

What this means in practice is that high sensitivity is not a deficit. It is a form of specialisation. The trait exists in approximately 20% of the population because the remaining 80% do not need it. Different strengths serve different functions, and this one has persisted because it continues to serve a purpose.

The Four Core Characteristics

Dr Aron’s research outlines four key characteristics that together define sensory processing sensitivity. As practitioners, having a clear understanding of these can help us recognise the trait in our clients and respond to it appropriately.

The first is depth of processing. Highly sensitive people tend to process information at a much deeper level than the general population. They reflect extensively before acting, notice layers of meaning that others might miss, and have a heightened level of self-awareness. This can be an enormous strength, though it can also contribute to overthinking, decision fatigue, and a tendency to become mentally or emotionally drained more quickly than others.

The second is overstimulation. Because the sensitive nervous system is taking in and processing so much from the environment at any given time, it reaches a threshold of overwhelm more readily. This is not about being fragile. It is a physiological response rooted in how the nervous system is wired. Clients who are highly sensitive may find busy environments, tight deadlines, or high levels of social interaction genuinely depleting in ways that can be hard to articulate or justify to others.

The third is emotional reactivity and empathy. Research has found that highly sensitive people have more mirror neurons, which are the neural structures responsible for empathy and emotional resonance. There is also greater activity in the areas of the brain associated with emotional processing. What this means practically is that HSPs feel emotions with considerable intensity, both their own and those of the people around them. For clients in helping professions, or for those in emotionally demanding relationships, this can be a particular source of exhaustion.

The fourth is sensitivity to subtleties. Highly sensitive people tend to notice things that others do not: shifts in tone, nonverbal cues, changes in atmosphere, or sensory details such as lighting, sound and smell. This heightened perceptual awareness is part of what makes them such thoughtful and empathic individuals, though in overstimulating environments, it can quickly become overwhelming.

The Neurobiological Basis

For practitioners who want to understand the science more deeply, there are clear neurobiological mechanisms that help explain high sensitivity. One example is the serotonin transporter gene. Those who carry a shorter version of this gene tend to have a more reactive amygdala, which is the structure within the limbic system responsible for processing emotion and registering threat. This heightened amygdala reactivity is one of the reasons why highly sensitive people respond more strongly to both positive and negative experiences.

It is also worth noting that environmental factors play a role in how the trait expresses itself. Chronic stress, for instance, has been shown to increase the size of the amygdala, which means that early adverse experiences can amplify the sensitivity that is already present. This has significant implications for how we work with HSP clients, particularly those who have experienced difficult childhoods or prolonged periods of stress.

Gender and Cultural Context

One thing that is important to acknowledge in a clinical or coaching context is that high sensitivity appears equally in men and women, yet men are considerably less likely to identify with the trait or seek support in relation to it. This is largely a cultural issue. Sensitivity is frequently equated with weakness, particularly in men, and so these traits are often suppressed, masked, or dismissed from an early age.

This means that male clients who are highly sensitive may present quite differently. They may have developed coping strategies that obscure the trait, or they may carry a great deal of shame around aspects of their experience that are in fact entirely consistent with who they are. Creating a non-judgmental space in which sensitivity is normalised and reframed as a strength is often a foundational part of the work.

Implications for Practice

For coaches and therapists working with highly sensitive clients, the research provides a genuinely useful framework. When a client understands that their experience has a biological basis, that it is innate rather than acquired, and that it has evolutionary value, it can be profoundly validating. Many HSPs have spent years believing that something is fundamentally wrong with them. Introducing them to this research can be one of the most significant turning points in the therapeutic or coaching relationship.

From a practical standpoint, it means thinking carefully about the environment in which we work, the pacing of sessions, the emotional demands we place on clients between appointments, and the language we use to describe their experiences. It also means recognising that the goal is not to make a highly sensitive person less sensitive. The goal is to help them understand their trait, work with it rather than against it, and build a life that genuinely supports their nervous system.

Want to Go Deeper?

If this has resonated with you and you would like to develop the specialised skills needed to work confidently and effectively with highly sensitive clients, I would love to invite you to explore my 3-Month Professional HSP Coach Training. This online programme takes a holistic and integrative approach to coaching HSPs, drawing on transpersonal psychology, trauma-informed practice, self-compassion, shadow work and more. The cohorts run in May and September, and spaces are intentionally kept small. You can find out more and enrol at highlysensitivehumanacademy.com.