Expression of the Emotions in Man and Animals

This book, published in 1872, is Charles Darwin's third major work on evolutionary theory.

It delves into the biological aspects of emotional behavior, arguing that human emotional expressions have their origins in animal behavior.

Darwin introduces principles such as 'the principle of serviceable associated Habits', 'the principle of Antithesis', and 'the principle of actions due to the constitution of the Nervous System'.

He analyzes various emotions and their expressions, highlighting the universal nature of these expressions across different species and cultures.

The book was illustrated with photographs, drawings, and woodblock prints, making it one of the first scientific works to use photographs extensively.

Darwin's work challenged the prevailing view that human facial muscles were divinely created for unique emotional expressions, instead linking them to evolutionary heritage.