Here are some examples from Darwin's 1872 work, The Expression of the Emotions in Man and Animals, a book illustrating human behaviors....
And the Flickr comments people have left on them.
1. "Contempt."
2. "Expressions of grief."
3. "Fear."
And here are some examples from an 1862 book by Duchenne de la Boulogne called Mecanisme de la Physionomie Humaine, filled with photographs exploring the muscles of facial expression (unlike the Darwin book, these are unlabeled)...
And the Flickr comments people have left on them.
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