‘The Expression of the Emotions in Man and Animals’, first published in 1872, followed in the wake of ‘The Origin of Species’ and ‘The Descent of Man’. Although an important landmark in early behavioural studies, it was probably overshadowed by Darwin’s earlier works of great importance and is thus not as well known as his other writings.

This book is not, as is sometimes made out to be, an explicitly comparative study of emotions in man and animals to establish the continuity of emotions. It is actually an investigation into the nature and origin of the expression of emotions. The questions Darwin intended to answer were more on the lines of how far particular movements of the features and gestures are really expressive of certain states of the mind and why certain muscles, and not others, contract under the influence of certain emotions. To this end he took an evolutionary approach, for he believed that the creationist assumption of immutability of species, adopted by most authors of the time, hindered a thorough investigation into the causes of emotions.

Darwin presents six lines of evidence to try and answer the questions he posed; of these, he gives most importance to the close observation of expression of several ‘passions’ in the ‘commoner’ animals. The other evidence stem from, for reasons that he explains in the introduction to the book, the observation of babies, impressions of observers about the emotion best expressed by photographs of the face of an old man when certain muscles were galvanized, study of emotions in paintings and sculpture, notes from observations of the insane, and notes on the expression of emotions in various races of human beings. The book thus brings together vast amounts of evidence from diverse fields like physiology, psychology, psychiatry, the arts and animal behaviour. As is characteristic of Darwin, there are no hand-waving arguments or enthusiastic, but unwarranted, interpretations; instead he conducts a patient appraisal of the available evidence and puts forward arguments supported by extremely insightful observations replete with detailed descriptions of behaviour.

What makes the book special, though, is how effortlessly and without hesitation Darwin bestows upon animals all that Descartes had denied them: feelings, emotions, volition. There is thus an important extension here of the doctrine of evolution of species, one that implies morphological, behavioural and mental continuity not just over evolutionary time as species evolve, but within the extant species as well. Although not explicitly sketched out in the text, the psychological continuity emerges as we are led to closely examine the emotions and behaviour of animals and man. ‘The Expression’ is thus a remarkable treatise, far ahead of its time, and an immensely significant forerunner to the development of fields like comparative psychology, which were eventually to give rise to disciplines like animal cognition and cognitive ethology that today delve into animal minds.

Further reading
Charles Darwin. 1872. The Expression of the Emotions in Man & Animals. London: John Murray.

Sartaj S Ghuman is a PhD student at the National Institute of Advanced Studies, Bangalore, India. Mail at batalaland@gmail.com