Answer :
Final answer:
Darwin posited the universal nature of human facial expressions based on evolutionary principles, suggesting that they may have a genetic basis and play a role in human evolution, a concept further evidenced by later empirical research.
Explanation:
Charles Darwin suggested in his book The Expression of the Emotions in Man and Animals (1872), that the universal nature of facial expressions across human cultures is tied to evolutionary principles. Darwin's insights were a precursor to modern research, such as that by Paul Ekman, who provided empirical evidence for the universality of human facial expressions associated with emotions like happiness, surprise, sadness, and anger. These expressions are considered universal because they are observed across diverse cultures and even in congenitally blind individuals who have never observed them in others. This suggests that facial expressions may have a genetic basis and could have played a role in human evolution by facilitating nonverbal communication, which is crucial for social interaction.