Highly sensitive person
Highly sensitive person (abbreviated HSP; sometimes capitalized Highly Sensitive Person in the popular press) is the psychology term first popularized in the mid-1990s to denote a person having a high measure of the innate trait whose scientific name is sensory processing sensitivity (SPS). Here, sensory processing refers to what occurs as sensory information is transmitted to or processed in the brain. SPS is measured by the Highly Sensitive People Scale (HSPS), which can be divided into subscales.
Highly sensitive people, who comprise about 15-20% of the population, process sensory data more deeply due to the biological nature of their nervous systems. This depth of processing underlies HSPs' greater proclivity to overstimulation, emotional reactivity and empathy, and sensitivity to stimuli.
Especially in Western culture, being highly sensitive is often judged to be socially and culturally unacceptable, and the sensory processing sensitivity (SPS) that characterizes HSPs has been wrongly confused with disorders whose outward behavior appears to resemble SPS. However, SPS is not a considered a disorder and has been shown to have benefits and advantages, both for the individual HSP and for society.
- 1 Origin and development of the term HSP
- 2 Attributes and characteristics of HSPs
- 3 Practical implications for the individual HSP
- 4 Measuring sensitivity, and the HSP category
- 5 Background and underlying principles
- 6 Related concepts
- 7 Distinguishing HSPs
- 8 Sources and notes
- 9 Further reading
- 10 External links
Origin and development of the term HSP
The phrase "highly sensitive person" had been used before the 1990s, such as colloquially to denote the opposite of "tough" or even technically as an indication of affective sensitivity (empathy). However, in the mid-1990s Drs. Elaine and Arthur Aron first formally identified sensory processing sensitivity (SPS), the scientific term for high sensitivity, as the defining trait of highly sensitive persons. In the context of HSPs, sensory processing refers not to what occurs within the sense organs themselves, but as sensory information is transmitted to or processed in the brain. Studies have shown that HSP brain scans show differences in neural activity compared with non-HSPs.
In 2015 The Wall Street Journal's Elizabeth Bernstein wrote that HSPs were "having a moment," noting that several hundred research studies had been conducted on topics related to HSPs' high sensitivity, and that a First International Scientific Conference on High Sensitivity or Sensory Processing Sensitivity had been held at the Vrije Universiteit Brussel.
Attributes and characteristics of HSPs
The sensory processing sensitivity (SPS) that defines HSPs has been described as "a temperament/personality trait characterized by social, emotional and physical sensitivity." More specifically, HSP attributes have been summarized by the mnemonic DOES: Depth of processing, Overstimulation because of the depth of processing, Emotional reactivity and empathy, and Sensitivity to stimuli.
HSPs have been described as having qualities of low risk taking, need for quiet (usually alone), high motivation to avoid overstimulation, preference for deeply meaningful conversations, greater awareness of subtleties in emotional and non-verbal communication, and a sense of being different and not the ideal. More specifically, HSPs report having sensitivity to subtleties, the arts, caffeine, hunger, pain, change, overstimulation, strong sensory input, others' moods, violence in the media, and being observed.
HSPs are thought to embody a strategy of thoroughly processing information about a novel situation before acting (exploring psychologically), as distinguished from a strategy of novelty seeking (advancing immediately and exploring physically).
Different components of sensitivity have been identified, some componenets being considered advantageous and some not. In particular, high scores in threshold sensitivity and ease of excitation have been associated with negative emotions, anxiety and depression; in contrast, high aesthetic sensitivity scores correlate with positive emotions, appreciation of beauty, greater attention to detail, communication skills, and openness to experience.
Practical implications for the individual HSP
HSPs' deeper processing of and greater responsiveness to both positive and negative stimuli motivates learning, and often leads to more successful responses in similar situations in the future. However, this deeper processing does not clearly manifest as an outwardly observable behavior, contributing to both laymen and health professionals wrongly misattributing SPS to traits thought to be undesirable, such as neuroticism, shyness, inhibition, unlikeability and lack of intelligence.
Though much attention has been given to undesirable sensitivity to negative influences (such as more highly negative responses to environmental adversity), greater benefits and advantages of higher sensitivity to positive influences have also been recognized, both for society (e.g., increased responsiveness to others’ needs stabilizing cooperative relationships and trust) and for the individual (e.g., security of attachment derived from sensitive parenting, academic achievement resulting from high-quality child care, prosocial behavior in response to supportive friendship networks, and life satisfaction stemming from positive life events).
Like other socially reticent behavior with which it is often confused, sensitivity has been linked to lack of peer acceptance and has even been associated with deviance, at least in Western culture. This social and cultural unacceptability adds to fear of social evaluation and other environmental stressors, and can result in lower self-esteem for HSPs. In particular, the stress of an adverse childhood environment is thought to lead to greater negative affectivity for adult HSPs than for non-HSPs of similar backgrounds.
HSP students pick up on subtleties and may think about them a long time before demonstrating their grasp of a subject. If an HSP student is not contributing much to a discussion, it does not necessarily mean he or she does not understand or is too shy. HSPs often have insights they are afraid to reveal because they differ from the common view, or because speaking up is too over arousing for them.
In a work environment, HSPs can be good with details, thoughtful and loyal, but tend to work best when conditions are quiet and calm. Because HSPs perform less well when being watched, they may be overlooked for a promotion. HSPs tend to socialize less with others, often preferring to process experiences quietly by themselves.
Measuring sensitivity, and the HSP category
In 1997 Drs. Elaine N. Aron and Arthur Aron formally published the Highly Sensitive People Scale (HSPS), consisting initially of 27 questions such as "Are you easily overwhelmed by strong sensory input?" and "Do you tend to be more sensitive to pain?" Aron and Aron reported acceptable reliability coefficients (α = .85 or .87) for the HSPS as a unidimensional measure of SPS, as well as content, convergent, and discriminant validity.
Smolewska et al. (2006) demonstrated that Aron's unidimensional HSPS was a valid and reliable measure of SPS, and further that the scale can be divided into a three-component structure including Aesthetic Sensitivity (AES, having greater awareness of beauty), Low Sensory Threshold (LST, easily unpleasantly aroused by external stimuli), and Ease of Excitation (EOE, easily overwhelmed by stimuli). In particular, LST and EOE are associated with the threat- and punishment-related behavioral inhibition system (BIS) and correlate with negative life outcomes, whereas high AES scores are associated with the dopamine system and correlate with greater psychological well-being.
At the time of The Highly Sensitive Person (1996), E. Aron had inferred from Jerome Kagan's studies of inhibitedness in children, that high sensory processing sensitivity (high SPS) should define a qualitatively distinct category, an inference supported by accumulated research (N>2000 as of 2012) indicating HSP Scale score patterns are distributed like an approximately dichotomous categorical variable and not continuously in a single normal distribution. This early (1996) lack of direct evidence was filled by a separate 2012 study (N=898 subjects) in which three taxometric methods evidenced SPS as a categorical variable (warranting a category qualitatively distinguishing HSPs from non-HSPs) rather than a dimensional variable (which would have implied HSPs differ from non-HSPs merely as a matter of degree).
Background and underlying principles
Evolutionary foundations and innateness
The sensory processing sensitivity trait defining HSPs is explained in part by the evolutionary development in various species of two personality types that manifest distinct survival strategies, namely, '‘pausing before acting’' (allow neural processes to assess survival-related subtleties in the environment), and '‘acting first'’ (to respond quickly to opportunities and discover survival-relevant cues through motor exploration). Humans are among more than 100 species found empirically to have subpopulations of individuals who both coexist and consistently display respectively different levels of responsiveness to environmental stimuli. An evolutionary basis for this phenomenon has been explained through negative frequency dependence (explaining coexistence) and when costs of responsiveness are lower for individuals who have previously been more responsive (explaining consistency).
After reviewing studies from the 1970s through the early 1990s concerning innate shyness, adult introversion, and childrens' inhibitedness, as well as similar traits in non-human species, Drs. Elaine and Arthur Aron reported seven studies and formally introduced (1997) sensory processing sensitivity (SPS) as a "core variable" thought to underlie the two complementary evolutionary survival strategies ("quiet vigilance" versus "exploration") activated in the face of novel stimulation. Aron and Aron posited that, like already-recognized gender-based and timid-versus-bold survival strategies, these two HSP-based survival strategies constitute an end product of natural selection rather than its raw material.
Early research had confirmed that, consistent with the diathesis–stress model, high sensory processing sensitivity (SPS) increased the correlation between negative environmental influences (e.g., adverse parenting) and negative affective (emotional) outcomes (e.g., adult shyness). Despite the traditional focus of psychiatric genetics on negative concepts of environmental adversity and genetic vulnerability, the differential susceptibility hypothesis suggested (2009) that high SPS would also increase correlation between positive environmental influences and positive affective outcomes. In such subsequent studies, high innate SPS was found to allow HSPs to be more responsive to positive environmental influences than non-HSPs. For example, in studies reported in 2013, only children scoring in the upper third of the HSP Scale experienced a decrease in depression symptoms in response to a school's resilience-promoting program in a deprived metropolitan area; and emotional affects of HSPs were found more responsive to the emotional reward of successfully completing tests.
More broadly, SPS research may be considered to refine the "personality-situation debate"—the personality theory embodiment of the larger nature versus nurture debate; the SPS research indicates that high innate sensory processing sensitivity (nature) is what underlies HSPs' greater responsiveness to their environments (nurture).
To study the neural foundations of sensory processing sensitivity (SPS), functional magnetic resonance imaging (fMRI) technology was used to determine whether stronger neural activity would be found in predicted brain regions in response to both positive and negative social stimuli. Greater activity was found in HSPs' brain regions involved in attention, empathy, higher order cognitive processing, action planning in response to "close others" (non-strangers; particularly to their positive emotions), integration of sensory information, emotional meaning making, self-other processing, the mirror neuron system, and self-awareness.
These positive findings for neural responses to social stimuli paralleled results of the first (2011) fMRI neural investigation of SPS, which found SPS to correlate with both increased response time and increased brain-region activation in response to subtle changes in non-social stimuli (specifically, a change-detection task involving landscape photographs). Still other fMRI testing confirmed greater regional brain activation during culturally non-preferred tasks, with higher-SPS subjects showing little cultural difference, indicating HSPs' judgments are based on more thorough processing of actual stimuli and less by cultural context.
Genetic foundations and innateness
Sensory processing sensitivity (SPS) has been indicated to be substantially innate (of genetic origin) as opposed to learned (of environmental origin). For example, studies show SPS' association with polymorphisms of a variant of the 5-HTTLPR (serotonin-transporter-linked polymorphic region), and relate contributions to SPS from polymorphisms in dopamine neurotransmitter genes (accounting for 15% of the variance in HSP measurement compared to 2% for the tested environmental factor, stressful life events).
The sensory processing sensitivity (SPS) concept was intended to encompass what adult personality researchers have variously described as: weak nervous system (Pavlov), low screening (Mehrabian), augmenting (of stimulation; Petrie), reducing (of evoked potential; Buchsbaum, Haier, & Johnson), reactivity (Strelau), avoidance temperament (Elliot & Thrash), and nondisinhibition or reflectivity (Patterson & Newman), and what child temperament researchers have described as inhibitedness (Kagan), infant (or innate) shyness (Cheek & Buss; Daniels & Plomin), reactivity (Rothbart; Strelau), and threshold of responsiveness (Thomas & Chess). SPS has also been related to innate sensitiveness (Jung), arousal focus (Feldman), and the physiological differences underlying introversion and extroversion (Eysenck; Stelmack; Stelmack & Geen). Other concepts of the trait include coping style, reactivity, flexibility, plasticity, and differential susceptibility.
In work pre-dating (1981) the SPS model, Eysenck defined introversion in terms of avoidance of arousal, a term that McNaughton and Gray subsequently (2000) described as "slippery" before concluding that there are multiple, neurally distinct types of arousal. Gray initially (1982) conceived a behavioral inhibition system (BIS) that is responsive to signals of punishment and non-reward, novel stimuli and innate fear, with Amodio et al. later (2008) refining the concept of inhibition to emphasize a pause in behavior to monitor for response conflicts ("pause to check") rather than actively engaging in avoidance behavior per se.
Research in developmental psychology provides evidence that individuals differ in their sensitivity. According to the differential susceptibility hypothesis by Belsky (1997b; 1997a; 2005) individuals vary in the degree they are affected by experiences or qualities of the environment to which they are exposed. Showing that children thought to have difficult temperaments in infancy were merely more susceptible to the effects of both low- and high-quality child care before age 5, Pluess & Belsky used the term vantage sensitivity to describe the trait and to highlight its evolutionary advantages.
According to the model of sensory processing sensitivity (SPS) that characterizes HSPs, variations in SPS underlie various trait differences such as introversion versus extraversion, inhibited versus uninihibited (children), and timid versus bold survival strategies, but SPS itself—modeled as the basic variable rather than a secondary variable—is itself distinct from these traits. Further, while some outwardly similar traits may be considered to be disorders, high SPS is not considered to be a disorder.
Distinguish: shy people
Shyness has been defined as a fear of negative social evaluations, leading to discomfort that limits desire for social contact. In contrast, the high sensory processing sensitivity (SPS) that characterizes HSPs does not inherently involve such fear, though the SPS model indicates that SPS increases the effect of negative environmental stressors (such as adverse parenting) and may cause negative affective (emotional) outcomes (such as adult shyness).
Distinguish: Dabrowski's over-excitability
Dr. E. Aron, the mid-1990s propounder of the term HSP, responded to Susan Cain's 2012 book Quiet: The Power of Introverts... and its related Time cover story by stating that Cain's adopted definition of introverts matches Aron's definition of HSPs, that introversion is more commonly defined in terms of social interaction, and that 30% of HSPs are social extroverts.
Distinguish: high sensation seekers (HSS)
Although HSSs may seem to be the opposite of HSPs, a person who takes many risks acts without reflecting very much is the opposite of an HSP; an HSP who is also an HSS will find ways to have novel experiences without taking ill-considered risks.
Distinguish: people with sensory processing disorder
Distinguish: people on the autism spectrum
People with autism spectrum disorder (ASD) may be confused with HSPs because of avoidance behaviors that may appear outwardly for both. However, while those with ASD have difficulty perceiving and interpreting social and emotional cues, HSPs are very aware of such cues and relate well socially once familiarity is achieved.
Sources and notes
- Bernstein, Elizabeth (May 18, 2015). "Do You Cry Easily? You May Be a ‘Highly Sensitive Person’". The Wall Street Journal. Archived from the original on June 1, 2015.
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- Aron, Elaine (1996). The Highly Sensitive Person, Preface at page xiii.
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- See, for example, Duka, John (March 28, 1981). "Evangeline Gouletas: She Enjoys Her Business and Her Privacy". The New York Times. Archived from the original on May 24, 2015. ("I am not a tough person at all," she said. "I lead people and I am highly sensitive to their needs. I am strong and disciplined and there is a big difference between that and being tough." ... Of Governor Carey, she would say only: "I think he is a highly sensitive person as well.")
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(Most discriminating items contained correct answer statements describing fairly strong client emotions. The highly sensitive person accurately identified the statement but the person low in sensitivity was attracted to a moderate or neutral statement.)
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