Before revision: Robert Zajonc , a University of Michigan psychologist, published two reviews in 1989 of the "facial efference theory of emotion", also known as facial feedback theory, which he had first introduced to the scientific literature in an article published in Science in 1985.
After revision: Robert Zajonc published two reviews in 1989 of the "facial efference theory of emotion", also known as facial feedback theory, which he had first introduced to the scientific literature in an article published in Science in 1985.