Are you anxious, introverted or just a ‘highly sensitive person’?

Do you find yourself noticing faint sensations that no one else can perceive? Are you startled easily? And is your mood easily swayed by the feelings of the people around you? If so, you may be a highly sensitive person (HSP), a personality profile that is of increasing interest to both scientists and armchair psychologists.

As an HSP myself, the trait is most obvious in my embarrassing squeamishness; at the merest hint of violence or pain on TV, I will reflexively cover my eyes with my hands. For other HSPs, their greater sensitivity may be especially evident in an intolerance of strong scents or bright lights, or great discomfort in large crowds.

A host of celebrities – including Alanis Morissette, Kanye West, Nicole Kidman and Lorde – have come out as HSPs in the past few years, and the term is increasingly used in the pages of lifestyle magazines and self-help blogs.

High sensitivity is often presented as a key contributor to depression and burnout. “A lot of people still think of it in terms of risk and vulnerability,” says Prof Corina Greven of the Radboud University medical centre in the Netherlands.

The truth, however, is more complicated. Both high and low sensitivity can have advantages and disadvantages – it all depends on the context. And with a bit of self-knowledge about our place on the spectrum, we can all learn to find the right coping mechanisms to make the most of our personality profile.

Hysteria

The idea of a highly sensitive person may seem to recall 19th-century diagnoses of neurasthenia and hysteria, when “rest cures” were frequently prescribed for the overstimulated. The modern interest in HSPs first took root in the mid-1990s, however, with the research of American psychologists Elaine and Arthur Aron.

Their aim was to capture someone’s “sensory processing sensitivity” – their excitability in the face of physical, social or emotional stimuli. It didn’t matter whether the nature of the excitement was positive (through, for example, an appreciation of beautiful art or a lively conversation) or negative (through heightened feelings of stress); the point was to learn how forcefully the central nervous system reacted to stimulation.

To do so, the researchers designed a series of questions that could be answered on a scale of 1 (not at all) to 7 (extremely). The items included:

• Do you find yourself needing to withdraw during busy days, into bed or into a darkened room or any place where you can have some privacy and relief from stimulation?

• When people are uncomfortable in a physical environment do you tend to know what needs to be done to make it more comfortable (such as changing the lighting or the seating)?

• Do you find it unpleasant to have a lot going on at once?

• Does being very hungry create a strong reaction in you, disrupting your concentration or mood?

• Are you deeply moved by the arts or music?

The questionnaire is known as the HSP scale and the top 20% were considered to be HSPs. Subsequent research revealed that people’s scores are correlated with measures of introversion – but the differences are large enough that the two traits can be considered distinct. “Not everyone who is highly sensitive will be introverted as well,” says psychologist Dr Charlotte Booth, a research fellow at University College London.

In general, people with HSP report being more perceptive across many different domains. They may find it easier to pick out faint sounds that no one else can hear, for example – but they also report being more attuned to others’ needs. As one study participant recently told Greven: “I can just look around the group and immediately spot who is feeling well and who is fighting as a couple, or where there’s tension.” High sensory processing sensitivity also manifests in different thinking styles. “It’s also linked to taking longer to make decisions, greater reflection and enjoying deep conversations over small talk,” Greven says.

Eva Pama-van ‘t Zand, a psychologist in the Netherlands, describes it as feeling like a small boat on a lake that is surrounded by larger ships. While others remain steady, you are rocked by the smallest of ripples. At its best, her high sensitivity means that a single smile from a stranger can lift her whole mood: “My experience of the world is richer.” During busy periods, however, the intensity of her feelings can leave her “feverish”.

While some cynics may be sceptical of any trait measured through self-report, people’s scores on the HSP scale do seem to reflect objective differences in the brain’s responses to its environment. More sensitive individuals seem to show greater reactivity in the sensory cortices associated with perceptual processing, as well as regions such as the insula and the amygdala that are involved with emotion. Importantly, they also show heightened activity in the prefrontal cortex and other areas that are involved in cognitive tasks such as planning and abstract thinking.

Together, these findings would seem to support the claim that HSPs are feeling the world more intensely. According to one recent paper, they are even more likely to experience “autonomous sensory meridian response” – those tingles in response to a whispered voice or the sound of brushing hair.

Like other personality traits, sensory processing sensitivity seems to be the product of nature and nurture. In 2020, Prof Michael Pluess of Queen Mary University of London asked 2,868 twins to take a version of the HSP scale designed for adolescents. By comparing the scores of the people who shared the same genetic blueprint and those who did not, he found that around half the variance between individuals could be explained by their genes.

It’s not yet clear what those genes may be. One potential candidate is the serotonin transporter gene (often referred to as 5-HTTLPR), which regulates the levels of the neurotransmitter around our synapses. Serotonin is known to modulate mood and attention, and different variants of the gene seem to promote more or less efficient serotonin processing than others – which could have immediate implications for someone’s responses to their environment. Despite some initial excitement, however, the gene’s link to sensory processing sensitivity seems to be relatively weak, and its importance may have been exaggerated. “Most likely, there are many thousands of variations across the genome that together explain a common trait of sensitivity – rather than a single gene,” Pluess says.

Dandelions and orchids

From the very beginning of the research into sensory processing sensitivity, psychologists have been trying to track the trait’s broader consequences for our long-term wellbeing. “Among those with mental health problems, the number of people with greater sensitivity is disproportionately high,” Pluess says.

Subsequent research has shown that the influence of sensory processing sensitivity depends on someone’s circumstances; it is not a universal risk factor. One study from Mary Washington University in the US examined people’s relationships with their parents and their current mental health. It found that high sensitivity significantly increased the chances of developing depression for those who had grown up with poor parental care. For people in loving homes, however, high sensitivity had no effect at all.

Booth found similar patterns with a sample of 185 adults from the UK: HSPs who had endured adverse childhood experiences showed much lower life satisfaction later in life, compared with less sensitive people. “They’re much worse affected by negative environments,” she says.

Intriguingly, however, HSPs are also more responsive to therapeutic interventions. In 2015, for instance, Pluess studied the effects of a prevention programme, based on cognitive behavioural therapy, that was delivered to schoolchildren at risk of depression over a year. He found that the programme was most effective at reducing depression scores among the children with high sensitivity, while it made little difference to those with low sensitivity. Their increased perceptivity seemed to help them to take on the lessons of the resilience training.

Such findings have led some researchers to compare highly sensitive persons to orchids – hothouse flowers that can only thrive when they are nurtured. People with less sensitivity, according to this theory, are more like dandelions – their welfare is generally less dependent on external support. (The people in the middle are sometimes known as tulips.)

High sensitivity may be especially relevant in the workplace. In teams with toxic dynamics, highly sensitive persons may be more susceptible to burnout and emotional exhaustion. Even if they are not bullied themselves, they will find their mood more easily shaken by the negative vibes around them. “They will probably pick up more on the tension around them, and find it uncomfortable,” says Pluess.

In a nurturing environment, however, greater sensitivity could be a real advantage. There is some evidence that HSPs are better able to pick up on implicit patterns that would escape others’ awareness. This may help them to learn new procedures, without needing someone to explain everything to them. They may also prove to be better listeners and team players, as they consider the needs of their colleagues. Managers should be aware of the trait’s pros and cons during recruitment, says Pama-van ‘t Zand: “It might help them to choose better candidates.”

Coping mechanisms

Twenty-five years after the Arons’ invention of the HSP scale, the existence of the trait should now be of little doubt. “We know that there are individual differences in sensitivity to environment,” says Greven. But she argues that we still need more robust research examining the neural mechanisms behind the trait and carefully describing its consequences.

With time, it may be possible to identify how psychological interventions could be tweaked to cater for people at different ends of the spectrum. “We could have a personalised approach,” says Pluess. That could include treatments that specifically address the difficulties of high sensitivity – such as the tendency to feel overwhelmed by stress. Equally importantly, we may need new approaches to help people with low sensitivity, who seem to respond less well to traditional psychological interventions and who may need very different forms of support. “You have to think about the other side as well,” says Booth.

Personally speaking, I’ve found that the mere knowledge of sensory processing sensitivity, and its influences on our lives, has been enormously instructive. I now understand why I gravitated to a career in writing, where I can happily devote myself to long stretches of concentrated work. Being an HSP has also helped to explain why I am often easily distracted by tiny gestures in social interactions – such as the tone of someone’s voice or a brief change in someone’s facial expression. And – superficially – it means that I need no longer feel embarrassed by my extreme aversion to horror films.

There can be room for all kinds of personality types in this world. Whether you are dandelion, tulip or orchid, you can find your niche.

• David Robson’s The Expectation Effect: How Your Mindset Can Transform Your Life is published by Canongate (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply