Why was the prison study by Haney et al. discontinued after six days?

The prison study conducted by Haney et al. was discontinued after six days primarily because the situation became unmanageable and raised serious ethical concerns. The study, which was designed to explore the psychological effects of perceived power in a simulated prison environment, led to extreme stress and distress among participants. The "guards" became increasingly authoritarian and abusive, while the "prisoners" experienced emotional breakdowns and showed signs of psychological distress. This escalation of negative behavior and the impact on the participants prompted the researchers to halt the study to prioritize the well-being and safety of everyone involved. The ethical implications of the participants' treatment were significant, highlighting the need for stringent ethical guidelines in psychological research.