In college, I studied abroad in Tartu, Estonia, and Fez, Morocco. After countless hours of walking and people-watching, I came to appreciate the starkly different emotional landscapes in both countries, especially in the case of anger.

One night in Tartu, I saw two men arguing in a city park. They exchanged words for a few minutes, now and again raising their voices. All of a sudden, one man clenched his fists and held them up like a boxer, ready to fight. I didn’t realize the Estonians were truly angry until they nearly came to blows.

Two months later, while making my way through Fez’s crowded medina, I became vaguely aware of distressed voices behind me. Suddenly, two young men burst into the street. They screamed and lunged at each other, twirling down the street in a furious melee. Several bystanders pulled the men apart, and then everyone continued on their way, as if nothing had happened.

Is anger an innate human emotion, an evolutionarily hardwired part of our behavioral repertoire? Or is anger a subroutine of our cultural programming, acquired without awareness?

In the 1872 book The Expression of Emotion in Man and Animals, Charles Darwin used technological advances of the day in photography and physiometry to undertake a scientific examination of the emotions, including anger.

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