• Lack of informed consent: The participants in the study were not fully informed about the nature of the experiment or the potential risks involved. They were told that they would be participating in a study on prison life, but they were not told that they would be randomly assigned to the role of prisoner or guard. This lack of informed consent could be considered unethical because it did not allow the participants to make an informed decision about whether or not to participate in the study.
• Harm to participants: The participants in the study experienced a significant amount of psychological harm. Some of the prisoners became so distressed that they had to be released from the study early. This harm could be considered unethical because it was not necessary for the purpose of the study.
• Deception: The participants were deceived about the nature of the study. They were told that they would be participating in a study on prison life, but they were not told that the study was actually designed to test the hypothesis that people will conform to their assigned roles, even if those roles are harmful. This deception could be considered unethical because it violated the participants’ trust.
• Abuse of power: The guards in the study abused their power over the prisoners. They subjected the prisoners to humiliation, degradation, and physical and psychological abuse. This abuse of power could be considered unethical because it violated the prisoners’ rights.
• Withdrawal from the study: The participants were not allowed to withdraw from the study at any time. This lack of freedom of choice could be considered unethical because it did not allow the participants to protect themselves from harm.

Based on the APA Ethical Principles of Psychologists and Code of Conduct, the Stanford Prison Experiment would not be considered ethical today. The APA ethical principles that were violated include:

• Beneficence and Nonmaleficence: Psychologists should strive to do no harm and to maximize benefits to their research participants. The Stanford Prison Experiment clearly did not do this, as it caused significant harm to the participants.
• Respect for People’s Rights and Dignity: Psychologists should treat their research participants with respect and dignity. The Stanford Prison Experiment violated this principle by subjecting the participants to humiliation, degradation, and physical and psychological abuse.
• Informed Consent: Psychologists should obtain informed consent from their research participants before conducting research. The Stanford Prison Experiment did not obtain informed consent from the participants, as they were not fully informed about the nature of the study or the potential risks involved.
• Deception: Psychologists should only use deception in research when it is justified by the potential benefits of the research and when there are no other feasible methods to obtain the data. The Stanford Prison Experiment used deception in a way that was not justified by the potential benefits of the research.
• Withdrawal from Research: Psychologists should allow their research participants to withdraw from the study at any time. The Stanford Prison Experiment did not allow the participants to withdraw from the study, which violated their right to self-determination.

In conclusion, the Stanford Prison Experiment was an unethical study that violated the APA ethical principles. The study caused significant harm to the participants and did not do any good for science. The study would not be considered ethical today and should not be replicated.