Some people have a stronger connection with sensations than others, a certain susceptibility to the slightest action or external aggression, « hypersensitive ». Is feeling more powerful an advantage or a disadvantage?
Article published in The Conversation by Evan Giret, PhD student in Psychology at 2LPN (EA 7489), University of Lorraine.
Allergy is a term that appears a lot around us – and often refers to different things. We can talk about sensitivity in relation to sensations, that is, the ability to test perception. We can also talk about susceptibility to the slightest action, external aggression, etc.
Far from just being allergic, some people are described as ‘hypersensitive’. This time it’s about suggesting that they are particularly emotional, easily shouting in front of romantic movies or on sad songs for example.
The term hypersensitivity, which has gradually spread among the general public for several years, generally refers – in part erroneously – to hyperesthesia (meaning « the senses are easily disturbed ») and abnormally frequent intense feelings. Here we will prefer the terms « high sensitivity » which are freed from the pejorative connotation of excess.
The manifestation of sensitivity can be internal, with a physiological reaction or emotion, or external, with a rebound gesture for example. It is always associated with a stimulus, internal (idea) or external (from the environment …) called the stimulus.
These stimuli can be of different nature: social (a call from a friend, a colleague comes to talk to us, a stranger challenges us on the street), emotional (the memory of a loved one, a hug from our pet, etc.), physiological (a grumbling stomach, a racing heart .. .) or sensory (auditory, olfactory, visual …).
Whatever it is, we are exposed to it on a daily basis. Humans, who depend on environmental resources for survival, must be able to capture, integrate, and process all of these stimuli to adapt.
But with a particular stimulus, we don’t all react the same way…
Sensitivity differences: what are they?
Most people react more or less identically to the same stimuli, and those who react more strongly are said to be more sensitive. Various theories have attempted to describe these differences and were grouped in 2016 under the general concept of « environmental sensitivity ».
The latter includes in particular the concept of sensitivity to sensory processing (SPS, measured by the HSPS self-report questionnaire), which is closest, from a theoretical point of view, to the so-called hypersensitivity in everyday language. It was introduced in 1997 by Eileen and Arthur Aaron and suggests that sensitivity is a personality trait characterized by:
- greater depth of information processing,
- Increased emotional reactivity and empathy,
- Increased awareness of environmental details,
- Ease of overstimulation.
This concept of environmental sensitivity is also intended as a meta trait, i.e. a high-level personal dimension, that captures and partially explains existing psychological concepts such as introversion, shyness, inhibition of behavior or reactive temperament.
This has powerful implications, particularly with regard to treatments and clinical diagnosis of mental illness or even research into the origin of certain mental disorders.
High sensitivity is often associated with negative effects
Historically, research on environmental sensitivity has mainly focused on the vulnerabilities of individuals. These weaknesses are associated with many factors (genetic, psychological or physiological) and will result in a higher sensitivity to different stimuli.
In other words, our internal characteristics influence the impact of the environment on us. For example, if an individual has a particular copy of a gene associated with a low expression of the serotonin transporter molecule (known as the happiness hormone), they are more likely to develop depressive symptoms during stressful events. So a genetic factor combined with negative stimuli can have serious consequences.
But we found bias in the studies that were conducted. Due to the majority of research linking vulnerabilities with high sensitivity, the vast majority of studies describe associations between negative environments (child abuse, parental insensitivity, negative life events…), high sensitivity and adverse consequences of the latter (predisposition to mental disorders or poor quality from life).
Therefore, high sensitivity is usually associated with some form of vulnerability, resulting in very few benefits on a daily basis and favoring complications in negative contexts. We can cite in particular the links between high sensitivity and social phobia, withdrawn personality disorder, anxiety and depression, autonomic stress, agoraphobia, alexithymia, autism spectrum disorder or even difficulty regulating emotions.
But are we really susceptible to these harmful consequences if we are hypersensitive?
Research on the heritability of susceptibility reveals that genetic influences explain 47% of its variance, and the remaining 53% are due to environmental influences. This indicates that sensitivity is an inherited trait. However, if it is heritable, it must present an adaptive advantage, even if slight (or at least not handicap), to be conserved across generations by natural selection.
This trait may be evolutionarily conserved for a very long time, as it is present in other mammalian species as well (a valid measure of canine sensitivity appeared in 2017).
Numerical simulations and experimental research simultaneously indicate that high sensitivity would be beneficial if it is present in 15-20% of the population, making it a low frequency dependent trait. This reflects, within the group, the fact that the individuals who compose it can choose different strategies, particularly thanks to their differences in sensitivity, in order to better adapt to the differences in their environment and to be more attentive.
Towards the potential benefits
For more than a decade, the positive effects of beneficial environments on highly sensitive individuals have been studied further.
In 2015, a study examining the link between high sensitivity and response to a depression prevention program conducted with teenage girls showed that sensitive people were more receptive to the help provided. Better: Changes were significantly greater for highly sensitive individuals.
In 2018, another study found a link between high sensitivity and response to a school-based anti-bullying intervention program. Not only were nuisances significantly reduced, but highly sensitive individuals contributed almost exclusively to the phenomenon.
Therefore, these studies indicate that highly sensitive individuals have a better ability for self-integration than others, for reflective thinking or even learning and awareness.
These findings are consistent with a brain imaging study showing that individuals with high sensitivity, when faced with positive or negative emotional stimuli, have increased brain activity in areas related to these abilities (hippocampus, parietal/frontal area, prefrontal cortex…).
In addition, if presented with positive images (if they had a positive childhood), they show increased activation of areas of calm, processing of others (partial cortex), and reward response (ventral ventral region, black locus, caudal nucleus) – the latter serving as a primary stimulus for survival It can be used for fun including addictive substances.
If they are given negative images, it is the areas related to self-control (the medial prefrontal cortex) and cognitive and emotional self-regulation that are over-activated.
Make the most of anaphylaxis
Research in addictions and mood disorders has demonstrated a role for the medial prefrontal cortex in self-control, and increased impulse control in response to positive stimuli is associated with reduced risk-taking and addiction.
This suggests that high sensitivity combined with a favorable development environment would be a protective factor against addiction: highly sensitive individuals would therefore be less likely to have excessive and problematic behaviors (internet-related, online gaming, “money…) or become dependent after taking drugs.
All of these studies agree on the key role that childhood quality and the environment play. With environmental factors contributing to about half of the sensitivity variance, it is necessary to reduce negative experiences (or mitigate adverse effects) that are exacerbated by the allergic trait.
Correct determination of individuals’ sensitivity level may be useful for estimating the success or lack of success of treatments and intervention programs – the latter being a success factor, so much so that research into gene therapy is now concerned with personalized psychotherapy.
Helping develop hypersensitive people
Thus, studies of environmental sensitivity do indeed contribute to explaining individual differences in development in particular contexts and to vulnerabilities to certain mental illnesses. They can also allow for early intervention to prevent abnormal developments in highly sensitive individuals while helping them thrive in a modern society, a source of difficult to manage triggers.
In the future, they will make it possible to better shed light on this trait, both in terms of the neural mechanisms involved and in terms of its origin or association with other disorders.
So high sensitivity or hypersensitivity can be a valuable asset! Far from being a mental disorder, it is a trait whose role in adaptation mechanisms to the environment is fundamental. The richness of its evolutionary, medical, and social implications has been outlined in numerous ongoing works, in psychology, genetic biology and neurosciences—enough to allow individuals already involved to transcend the often negative judgments they often remain a target.