Darwin’s book on emotions is an entertaining read. As ever, he makes many perceptive observations, describing how humans and animals express emotions. But he makes no real attempt to draw the two together
While Darwin gives examples of body-language we share with certain domestic animals, such as shaking or perspiring in fear, he wisely steers clear of making comparisons of ‘higher’ emotions. He doesn’t, for example, attempt to show similarities in body-language between affectionate dogs and humans. (Not least, presumably, because humans don’t have tails to wag!)
Darwin does eventually become a bit bolder when comparing the body-language of humans and other primates, describing how certain apes and monkeys ‘laugh’ when pleased, ‘chuckle’ and wrinkle their eyes when tickled, ‘weep’ when grieving, and ’pout’ when sulking. But he never explicitly presses home an argument claiming we and our fellow simians inherited common facial expressions from a common ancestor. His rhetorical technique seems to be to describe the similarities, but to let the reader work out the implications for themself.
Darwin is far stronger arguing for a common set of expressions across all humans. As someone who believed all mankind was descended from common human ancestors, Darwin thought we would most likely share a common set of emotions. This put him at odds with other evolutionary scientists of his day, who argued different races of humans had evolved from different non-human parent stock. Such arguments were used, along with other specious reasoning, to justify the subjugation of other races by what were assumed to be clearly superior white Europeans. As a fervent opponent of slavery (and, let’s face it, as a far better evolutionary scientist), Darwin had no time for such nonsense.
In one way at least The Expression of the Emotions in Man and Animals was a thoroughly groundbreaking book: it was the first scientific book written in English to contain photographs. And some of them are absolute belters.
The version of the book I read contained a useful running commentary by the psychologist Paul Ekman. It turns out much, but not all, of what Darwin said about the expression of emotions is still supported by modern experts in the field.