There are only seven expressions to choose from – these are what are referred to as the seven universal expressions. Charles Darwin was one of the first people known for researching emotion, believing emotions to be biological and universal. Paul Ekman’s studies of universal emotions with Wallace V. Friesen in Papua New Guinea demonstrated that even cultures that have no contact with the outside world share these universal seven emotions: happiness / joy, surprise, contempt, sadness, fear, disgust and anger. Studies done by David Matsumoto demonstrated that sighted and blind individuals produce the same facial muscle movements in response to emotional stimuli – even when they are blind from birth. This indicates that emotions are innate – we’re born with the knowledge of how to express these emotions through facial expressions. In my experience, disgust and anger can be easily confused, as well as fear and surprise.
Here’s a brief run down of each of the seven universal emotions:
Happiness / Joy: Genuine happiness is expressed with a Duchenne smile, which is expressed on the face by the combined contraction of the zygomaticus major muscle and the orbicularis oculi. In FACS terms, this is the lip corner puller AU 12 (of which is the voluntary part of a smile, which is also engaged when saying “cheese”, or clenching a pen in one’s teeth), and the cheek raiser AU 6 (which raises the cheeks and creates or increases crows feet). Click here to read an article I wrote on smiles.
Surprise: Involves the raising of the eyebrows and eyelids, and sometimes a dropping of the jaw. For more on surprise and telling it apart from fear, click here.
Contempt: This is identified by a half smile, half dimpler, or one sided lip raiser.
Sadness: The most reliable indicator of sadness is the raising of the inner corners of the eyebrows.
Fear: Similar to surprise, however includes the brow lowering. For more on surprise and telling it apart from fear, click here.
Disgust: Recognised most by the wrinkling of the nose or the raising of the upper lip. For more on disgust and telling it apart from anger, click here.
Anger: The main ingredients of anger include the lowering of the eyebrows, and the raising and tightening of the eyelids. This can also include any number of other factors such as clenching the jaw, gritting teeth or tightening the lips for example. For more on disgust and telling it apart from anger, click here.
Also check out my post on ranges in emotion.