What underlying societal mechanisms might explain why certain behaviors, such as cannibalism and incest, are considered taboo, while killing in self-defense is accepted?

Societal taboos are often based on shared values and beliefs that help maintain order and morality within a community. Behaviors like cannibalism and incest are seen as taboo because they threaten family structures and social bonds, which are crucial for the survival and stability of society. In contrast, killing in self-defense is accepted because it is seen as a necessary action to protect oneself from harm, reflecting a society's value on preserving life when it is under threat. For example, if someone is attacked, many people would agree that defending oneself, even with lethal force, is justified to ensure safety. This shows how our collective beliefs shape what is considered acceptable or unacceptable behavior.