Wilhelm Wundt introduced the word Gefühl from his native language to describe this inner experience. He began shaping how scientists understood human feeling during the 19th century. His work established affect as a distinct field worthy of its own study.
Affective states vary along valence, arousal, and motivational intensity. Valence represents the subjective spectrum of positive-to-negative evaluation an individual experiences during any given moment. Arousal measures objectively measurable activation of the sympathetic nervous system while also allowing for subjective self-reporting.
High motivational intensity narrows the cognitive scope regardless of valence. Anger and fear induce selective attention on specific targets because propulsion to act remains high. Researchers used flanker tasks with letters H and N to measure these differences in reaction times.
The Positive and Negative Affect Schedule serves as the most commonly used measure in scholarly research today. This lexical tool consists of 20 single-word items developed originally within a North American setting. An internationally reliable short form called I-PANAS-SF now comprises two five-item scales with cross-cultural validity.
Individuals low in affect tolerance show little to no reaction to emotion and feeling of any kind. This condition closely relates to alexithymia which involves difficulty identifying and describing feelings alongside bodily sensations. Persons with alexithymia demonstrate correlations with increased suicide rates mental discomfort and deaths according to Dalya Samur and colleagues.