Research has shown that highly sensitive people are more susceptible to perceiving subtle (internal and external) stimuli. In addition, they react more strongly to these stimuli (higher emotional reactivity), are more easily overwhelmed by incoming stimuli and more vulnerable to the effects of stress. Research also points at a potential link between hypersensitivity and psychological as well as somatic symptoms (e.g. fatigue).

In a first study, the psychometric properties of the Dutch version of the Highly Sensitive Person Scale (HSPS) developed by Aron and Aron (1997) were explored in a general population sample (N=998), a sample of patients suffering from (chronic) fatigue complaints (N=340), and a sample of chronic pain patients (N=337). Results demonstrated that the scale was a valid and reliable measure of the ‘Sensory Processing Sensitivity’ construct. A three-component structure, similar to the one identified by Smolewska et al. (2005) and consisting of Aesthetic Sensitivity, Low Sensory Threshold and Ease of Excitation was found in the population as a whole as well as in the different subsamples (manuscript submitted for publication).

An ongoing study explores to what extent Sensory Processing Sensitivity is associated with the Big Five personality dimensions, somatosensory amplification, anxiety, depression, and somatic complaints (pain, fatigue, and other somatic complaints).

During the validation process of the HSPS it became apparent that this scale offers however a restricted perspective on the Sensory Processing Sensitivity concept. Based on the current literature, several different dimensions can be distinguished within this concept, namely (1) (heightened) sensitivity to (subtle) sensory stimuli, including neutral perceptual sensitivity to both internal and external stimuli, affective sensitivity, and associative sensitivity, (2) sensory discomfort, and (3) emotional or physiological reactivity. The fact that these dimensions are not adequately covered by the HSPS developed by Aron & Aron (1997) was the starting point for the development of a more comprehensive Sensory Processing Sensitivity scale. A validation study of this questionnaire started in February 2018. Results are currently underway.