There is a lot of ongoing research in the area of high sensitivity, also known as Sensory Processing Sensitivity (SPS). This article shares a few highlights you may find of interest as a Highly Sensitive Person (HSP). I’ve included where I retrieved this information.

The functional highly sensitive brain: a review of the brain circuits underlying sensory processing sensitivity and seemingly related disorders (retrieved from https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2017.0161)

Abstract: During the past decade, research on the biological basis of sensory processing sensitivity (SPS)—a genetically based trait associated with greater sensitivity and responsivity to environmental and social stimuli—has burgeoned. As researchers try to characterize this trait, it is still unclear how SPS is distinct from seemingly related clinical disorders that have overlapping symptoms, such as sensitivity to the environment and hyperresponsiveness to incoming stimuli. Thus, in this review, we compare the neural regions implicated in SPS with those found in fMRI studies of— Autism Spectrum Disorder (ASD), Schizophrenia (SZ) and Post-Traumatic Stress Disorder (PTSD) to elucidate the neural markers and cardinal features of SPS versus these seemingly related clinical disorders. We propose that SPS is a stable trait that is characterized by greater empathy, awareness, responsivity and depth of processing to salient stimuli. We conclude that SPS is distinct from ASD, SZ and PTSD in that in response to social and emotional stimuli, SPS differentially engages brain regions involved in reward processing, memory, physiological homeostasis, self-other processing, empathy and awareness. We suggest that this serves species survival via deep integration and memory for environmental and social information that may subserve well-being and cooperation.

Acevedo B, Aron E, Pospos S, Jessen D. (2018), Review: The functional highly sensitive brain: a review of the brain circuits underlying sensory processing sensitivity and seemingly related disorders. Philosophical Transactions, B 373: 20170161.

Dandelions, tulips and orchids: evidence for the existence of low-sensitive, medium sensitive and high-sensitive individuals (retrieved from https://www.nature.com/articles/s41398-017-0090-6)

Abstract: According to empirical studies and recent theories, people differ substantially in their reactivity or sensitivity to environmental influences with some being generally more affected than others. More sensitive individuals have been described as orchids and less-sensitive ones as dandelions. Applying a data-driven approach, we explored the existence of sensitivity groups in a sample of 906 adults who completed the highly sensitive person (HSP) scale. According to factor analyses, the HSP scale reflects a bifactor model with a general sensitivity factor. In contrast to prevailing theories, latent class analyses consistently suggested the existence of three rather than two groups. While we were able to identify a highly sensitive (orchids, 31%) and a low-sensitive group (dandelions, 29%), we also detected a third group (40%) characterised by medium sensitivity, which we refer to as tulips in keeping with the flower metaphor. Preliminary cut-off scores for all three groups are provided. In order to characterise the different sensitivity groups, we investigated group differences regarding the Big Five personality traits, as well as experimentally assessed emotional reactivity in an additional independent sample. According to these follow-up analyses, the three groups differed in neuroticism, extraversion and emotional reactivity to positive mood induction with orchids scoring significantly higher in neuroticism and emotional reactivity and lower in extraversion than the other two groups (dandelions also differed significantly from tulips). Findings suggest that environmental sensitivity is a continuous and normally distributed trait but that people fall into three distinct sensitive groups along a sensitivity continuum.

Lionetti, F., Aron, A., Aron, E. N., Burns, G. L., Jagiellowicz, J. and Pluess, M. (2018). Dandelions, tulips and orchids: evidence for the existence of low-sensitive, medium-sensitive and high-sensitive individuals. Translational Psychiatry, 8, Article: 24

The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others’ emotions (retrieved from https://hsperson.com/pdf/The_highly_sensitive_brain_%20an_fMRI_study.pdf)

Abstract Background: Theory and research suggest that sensory processing sensitivity (SPS), found in roughly 20% of humans and over 100 other species, is a trait associated with greater sensitivity and responsiveness to the environment and to social stimuli. Self-report studies have shown that high-SPS individuals are strongly affected by others’ moods, but no previous study has examined neural systems engaged in response to others’ emotions. Methods: This study examined the neural correlates of SPS (measured by the standard short-form Highly Sensitive Person [HSP] scale) among 18 participants (10 females) while viewing photos of their romantic partners and of strangers displaying positive, negative, or neutral facial expressions. One year apart, 13 of the 18 participants were scanned twice. Results: Across all conditions, HSP scores were associated with increased brain activation of regions involved in attention and action planning (in the cingulate and premotor area [PMA]). For happy and sad photo conditions, SPS was associated with activation of brain regions involved in awareness, integration of sensory information, empathy, and action planning (e.g., cingulate, insula, inferior frontal gyrus [IFG], middle temporal gyrus [MTG], and PMA). Conclusions: As predicted, for partner images and for happy facial photos, HSP scores were associated with stronger activation of brain regions involved in awareness, empathy, and self-other processing. These results provide evidence that awareness and responsiveness are fundamental features of SPS, and show how the brain may mediate these traits.

Bianca P. Acevedo, B., Aron, E., Aron, A., Sangster, M., Collins, N., & Brown, L. (2014) The highly sensitive brain: An fMRI study of sensory processing sensitivity and response to others’ emotions. Brain and Behavior, 4, 580-594.

The Relationship between the Temperament Trait of Sensory Processing Sensitivity and Emotional Reactivity (retrieved from https://dspace.sunyconnect.suny.edu/bitstream/handle/1951/59701/Jagiellowicz_grad.sunysb_0771E_10998.pdf)

The results of these studies are important for a number of reasons. They provide unique support for the idea that SPS is associated with positive, and not just negative, emotions. They add to the evidence (Aron & Aron, 1997; Aron et al., 2012; Jagiellowicz et al., 2011) that SPS is distinct from neuroticism and introversion. They also add support to the evidence that there is an interaction between sensitivity and parental environment in which those who are highly sensitive are more influenced by their parenting. In a broader sense, the results support Aron’s (2010) argument that SPS is not itself a clinical condition. High SPS individuals who encounter positive events appear to be more affected for the good than those low in SPS. In sum, the present studies provide the first direct test of the relation of SPS to response to emotional stimuli. Results of both behavioral and neural measures suggest that SPS may be associated particularly with response to positive stimuli, and that this greater responsiveness of those high in SPS may be particularly strong for those with good parenting. 

Jagiellowicz, J., Aron, A., & Aron, E. N. (2012). Relationship between the temperament trait of sensory processing sensitivity and emotional reactivity. Social Behavior and Personality: an international journal, 44(2), 185-199.

Sensory Processing Sensitivity in the context of Environmental Sensitivity: A critical review and development of research agenda (The following information was retrieved from:  https://www.sciencedirect.com/science/article/pii/S0149763418306250?via%3Dihub)

•SPS captures sensitivity to environment in a heritable, evolutionary-conserved trait, associated with increased information processing in the brain.

•SPS moderates sensitivity to environments in a for-better-and-for-worse fashion.

•Interaction with negative experiences, increases risk for psychopathology.

•Interaction with positive experiences (including interventions), increases positive outcomes.

•Objective assessment, mechanistic understanding and evidence-based interventions for high scoring individuals on SPS need to be improved.

Abstract Sensory Processing Sensitivity (SPS) is a common, heritable and evolutionarily conserved trait describing inter-individual differences in sensitivity to both negative and positive environments. Despite societal interest in SPS, scientific knowledge is lagging behind. Here, we critically discuss how SPS relates to other theories, how to measure SPS, whether SPS is a continuous vs categorical trait, its relation to other temperament and personality traits, the underlying aetiology and neurobiological mechanisms, and relations to both typical and atypical development, including mental and sensory disorders. Drawing on the diverse expertise of the authors, we set an agenda for future research to stimulate the field. We conclude that SPS increases risk for stress-related problems in response to negative environments, but also provides greater benefit from positive and supportive experiences. The field requires more reliable and objective assessment of SPS, and deeper understanding of its mechanisms to differentiate it from other traits. Future research needs to target prevention of adverse effects associated with SPS, and exploitation of its positive potential to improve well-being and mental health.

​​Greven, C., Lionetti, F., Boothe, C., Aron, E., Fox. E., Schendang, H., Pluess, M., Bruining, H., Acevedo, B., Bijttebier, P., and Homberga, J. (2019), Sensory Processing Sensitivity in the context of Environmental Sensitivity: A critical review and development of research agenda. Neuroscience & Biobehavioral Reviews. Volume 98, March 2019, 287-305

Sensory Processing Sensitivity and the Subjective Experience of Parenting: An Exploratory Study  (retrieved from https://onlinelibrary.wiley.com/doi/10.1111/fare.12370)

Results: Controlling or not for external stressors, negative affectivity, children's age, and socioeconomic status, high-SPS mothers in both studies scored meaningfully higher on Parenting Difficulties and Attunement to Child; high-SPS fathers scored higher on Attunement to Child. SPS had little association with Coparenting Relationship.

Conclusion: Parents high in SPS report more attunement with the child, although mothers found parenting more difficult.

Aron, E. N., Aron, A., Nardone, N., & Zhou, S. (2019). Sensory Processing Sensitivity and the Subjective Experience of Parenting: An Exploratory Study. Family Relations.

 Observer-rated environmental sensitivity moderates children’s response to parenting quality in early childhood (retrieved from: https://psycnet.apa.org/record/2019-47142-001)

According to several developmental theories some children are more sensitive to the quality of their environment than others, but most supporting empirical evidence is based on relatively distal markers of hypothesized sensitivity. This study provides evidence for the validity of behaviorally observed Environmental Sensitivity as a moderator of parenting effects on children’s early development in a sample of 292 children (Mage = 3.74; SD = 0.26) and their mothers. Sensitivity was coded using a newly developed observational measure for the specific and objective assessment of Environmental Sensitivity, the Highly Sensitive Child-Rating System (HSC-RS). HSC-RS factorial structure, associations with temperament traits, and interactions with parenting quality in the prediction of socioemotional child outcomes are reported. Findings supported a 1-factor solution. Observed sensitivity was relatively distinct from observed temperament and interacted with both low and high parenting quality in the development of behavior problems and social competence at ages 3 and 6. (PsycInfo Database Record (c) 2020 APA, all rights reserved)

Lionetti, F., Aron, E. N., Aron, A., Klein, D. N., & Pluess, M. (2019). Observer-rated environmental sensitivity moderates children’s response to parenting quality in early childhood. Developmental Psychology, 55(11), 2389–2402.

I hope that seeing some of the research studies feel validating.  

While high sensitivity can be challenging to have in a world not set up for sensitivity, we know that we can thrive with the right support and tools. As a psychotherapist specializing in high sensitivity, I invite you to explore my website dedicated to empowering highly sensitive people to thrive to their fullest potential. www.juliebjelland.com

Free Resources

• Watch this video about high sensitivity 

• Give this letter to others to explain the sensitivity

• Give this letter to your medical and mental health professionals about high sensitivity and avoid misdiagnosis

• Take the free Sensitivity Quiz to see where you are on the spectrum of sensitivity

• RSVP for my free HSP Masterclasses teaching ways to lower the challenges of sensitivity so you can thrive in a world not set up for sensitivity

You are not alone. There are many of us supporting each other and sharing our sensitive journey together in the Sensitive Empowerment Community and we warmly welcome you to join us!

Julie Bjelland is a psychotherapist specializing in high sensitivity, Author of The Empowered Highly Sensitive Person, host of The HSP Podcast, and founder of the Sensitive Empowerment Community. Her books, blog, online courses, and free Masterclasses have helped thousands of highly sensitive people (HSPs) worldwide reduce their challenges, access their gifts, and discover their significant value to thrive to their fullest potential. Her HSPs in Heart-Centered Business Group connects and supports HSP healers and practitioners. Julie loves connecting in her Sensitive Empowerment Community and warmly invites you to join this positive, safe, and welcoming space. JulieBjelland.com❤️🌈❤️ (she/her)