James-Lange theory
We feel afraid because we tremble, not the other way around.
What it means
The James-Lange theory reverses the commonsense order of emotion, claiming that a stimulus first triggers bodily and physiological changes and that the felt emotion simply is the perception of those changes. On this view, the racing heart, tense muscles, and shallow breath are not consequences of fear but its very substance, so without bodily feedback there would be no emotion. The theory anticipated modern interest in interoception and embodied affect and is partially supported by findings that manipulating bodily states alters feelings. Cannon famously objected that bodily responses are too slow and too similar across emotions to account for our rich, rapid emotional life. Despite these criticisms, its core claim that the body shapes feeling has been revived in somatic and facial-feedback research.
Examples
Encountering a snake, your body recoils and your pulse spikes first; the conscious feeling of fear, James argued, is your reading of that bodily commotion.
Before a speech your hands shake and your mouth dries; on this account the nerves are not causing those signs — your sense of them is what the nervousness is.
Riders step off a rollercoaster with pounding hearts and shaking legs and call it exhilaration; strip away the racing body, James would say, and nothing of the thrill remains.
First described in William James (1884); Carl Lange (1885).