Why is cannibalism a universal taboo despite appearing throughout human history? A research team including Petr Tureček from the Faculty of Science, Charles University, developed a groundbreaking mathematical model. Published in PNAS, the study reveals that repeated consumption of one's own species causes a population collapse due to deadly diseases, which triggered the cultural taboo.
Cannibalism has fascinated humanity since time immemorial. Anthropologists and historians provide endless evidence of humans resorting to eating members of their own species during famines or rituals. Yet, across almost all cultures, there is a powerful taboo strictly forbidding this practice. A team of scientists, including biologist Petr Tureček from the Faculty of Science, Charles University, set out to solve this apparent paradox.
The research team looked at the human body pragmatically - as a potential source of energy. They built an advanced mathematical model comparing the energetic gains of cannibalism with the costs and risks of acquiring such food. The results show that from a purely nutritional perspective, a human is not a premium meal for another human, but rather an average one. The real twist came when the scientists factored in hidden biological costs.
The greatest threat comes from infection. In nature, pathogens are specialized to a specific host. If a human eats another animal, most of its diseases will not transfer. However, if a human consumes another human, the pathogens find themselves in a perfectly identical environment to which they are already adapted. It works like a computer virus: software programmed for a specific operating system will run flawlessly on any other computer of the same brand.
The ultimate danger arises when cannibalism forms a chain - meaning one cannibal eats another cannibal. In these consumption chains, the risk of disease transmission skyrockets. The model demonstrated that while a one-off act of cannibalism during extreme starvation can save a person's life, repeating the practice regularly leads to a swift spread of fatal diseases. These include prion diseases, such as kuru, which decimated indigenous tribes in New Guinea in the last century. Prions are heat-resistant, meaning even thorough cooking cannot protect people.
This research is groundbreaking because it connects cultural anthropology with mathematics and epidemiology into a single framework. It shows that moral and social taboos are not random cultural quirks. Instead, they are evolutionary defense mechanisms that humanity developed to protect itself from self-destruction.
“Our model clearly demonstrates that regular cannibalism is unsustainable for human populations in the long run. The epidemiological costs of spreading incurable diseases quickly outweigh any caloric benefits, reliably leading to community collapse. The cultural taboo therefore acts as an effective shield that protected our ancestors from this evolutionary trap,” explains Petr Tureček from the Faculty of Science, Charles University.
Bibliographic Citation
Misiak, M., & Tureček, P. (2026). The cannibalistic trade-off: Why human cannibalism emerges and why taboos suppress it. Proceedings of the National Academy of Sciences, 123(27), e2605120123. https://doi.org/10.1073/pnas.2605120123