Carroll Izard
Carroll Ellis Izard (October 8, 1923 – February 5, 2017) was an American research psychologist known for his contributions to differential emotions theory (DET), and the Maximally Discriminative Affect Coding System (MAX) on which he worked with Paul Ekman. Izard also undertook empirical studies into the facial feedback hypothesis according to which emotions which have different functions also cause facial expressions which in turn provide us with cues about what emotion a person is feeling.