A highly sensitive person (HSP) is a person having the innate trait of high sensitivity (or innate sensitiveness as Carl Gustav Jung originally coined it). According to Elaine N. Aron and colleagues as well as other researchers, highly sensitive people, which would represent about a fifth of the population, process sensory data much more deeply and thoroughly due to a biological difference in their nervous systems.[1] This is a specific trait with key consequences that in the past has often been confused with innate shyness, inhibitedness, innate fearfulness, introversion, and so on. [2] The existence of the trait of innate sensitivity was demonstrated using a test that was shown to have both internal and external validity.[3] Although the term is primarily used to describe humans, the trait is present in nearly all higher animals.
The term highly sensitive person was coined by Dr. Elaine N. Aron in 1996, and the name is gaining popularity because it presents the trait in a positive light, as it posits shyness, inhibitedness, fearfulness as negative traits that may or may not be acquired by highly sensitive people and animals, depending on environmental challenges. Yet other names used to describe the trait in literature include 'introverted emotional temperament', 'chronic cortical/cortisol arousal', 'hypervigilance', and 'innate shyness'.