The allure of violence is undeniable. It taps into something primal and evolutionary resonant. In the same way my harmless, domesticated wiener dog still has the hunting instincts to dig and follow scents, we still have the physical drive for survival encoded in our DNA despite almost never needing to act on it. As we’ve strived to rinse violence out of polite society, one of the many ways that drive manifests itself is through combat sports -- both the doing and the watching.

https://www.sherdog.com/news/articles/Different-Sides-of-Violence-170793