Is a dog's wagging tail or a cat's purring a sign of affection? Can animals experience emotions? If so, what does that mean for how we treat them? Are expressions really shared by all animals, including humans? These are some of the intriguing questions explored in Charles Darwin's, The Expression of the Emotions in Man and Animals: Definitive Edition (Oxford University Press, $30) with an introduction, afterword and commentaries by Paul Ekman, PhD, University of California San Francisco professor of psychology.
In 1872, Darwin published the first edition of The Expression of the Emotions in Man and Animals, in which he explained his theories of the universality of emotions, evolution and the continuity of species. During the first four months of publication in which 9,000 copies sold, the book proved to be a best-seller; however, sales declined dramatically thereafter and the book was eventually forgotten.
But now, more than 100 years later, Ekman has brought it back to life by returning to Darwin's original notes to produce a corrected authoritative text, illustrated by the original drawings and photographs Darwin intended to include, but were too expensive to reprint at the time. When it was originally published, The Expression was the first scientific book in English to contain photographic reproductions.
"Darwin's book is still the most comprehensive text available that explains the nature of emotions," says Ekman. "It is important to better understand and recognize expressions of human emotions because unlike thoughts which are private, expressions disclose what we are feeling."
In this book, Darwin answers many questions about emotions, but the most fundamental concept he addresses is whether we learn which emotions to make when we are angry, sad or happy, or whether such "knowledge" is innate. Darwin argues that human expressions of emotion are universal (meaning innate, not learned) and the product of our evolution and therefore part of our biology. Moreover, he says that neither our expressions nor our emotions are unique to human beings; but that we share them with other animals who have displayed expressions resembling those of humans.
Ekman, a leading researcher on facial expressions and emotions himself, originally intended to disprove Darwin's theory that emotions are universal. During the 1960's, Ekman traveled to the last existing stone age culture in Papa New Guinea to study people's expressions.
"I wanted to finally settle the argument about whether emotions are culturally specific or universal, and I found that Darwin was right," says Ekman. "There are at least seven emotions that have the same signals for all humans, regardless of their heritage, nationality or language."
He notes that this finding supports Darwin's argument on the unity of mankind and challenges racist theories that claim that one group of humans is superior to another because they descended from a more advanced species. Although Darwin's work did denounce racism, Ekman adds that, ironically, one of the reasons his book was neglected shortly after publication was because people believed it to be racist, although it is the exact opposite.
According to Ekman, in the last five years, a Darwinian renaissance has occurred in both the lay and scientific community. People no longer believe that one's environment, or nurturing, is the sole determiner of human behavior.
"This is a much more hospitable time for Darwin," Ekman says. "People have now accepted that nature and nurture both play a role in our behavioral development."