In all these [constructivist] views, an instance of anger or elation does not reveal its causal mechanisms—a marked contrast to the classical view, in which each emotion has a dedicated mechanism in the brain, and the same word (e.g., “sadness”) names the mechanism and its product. In recent years, a new generation of scientists has been crafting psychological construction-based theories for understanding emotions and how they work. Not every theory agrees on every assumption, but together they assert that emotions are made, not triggered; emotions are highly variable, without fingerprints; and emotions are not, in principle, distinct from cognitions and perceptions.

Lisa Feldman Barrett, How Emotions Are Made: The Secret Life of the Brain