Leading sci­en­tific thinkers of their time, such as Aris­totle, Rene Descartes, Guil­laume Duchenne, and Charles Darwin, have long pro­moted the idea that there are a handful of basic emo­tions that people express. In recent decades, that group has crys­tal­ized into six core emo­tions: hap­pi­ness, sur­prise, sad­ness, anger, fear, and disgust.

But there are clearly many shades of gray between those emo­tions. For example, there’s the happy-because-I’m-eating-ice cream and the happy-​​because-​​I-​​just-​​learned-​​I-​​got-​​a-​​surprise-​​marriage-​​proposal looks, each of which is slightly different.

That’s what intrigued Aleix Mar­tinez, asso­ciate pro­fessor of elec­trical and com­puter engi­neering at Ohio State Uni­ver­sity. “Six seemed a small number given the rainbow of pos­si­bil­i­ties of feeling and expressing emo­tions,” he says.

Read the article at Time →