Evaluation

• Haslam and Reicher’s BBC Prison Study (2006)


  When participants were randomly assigned to the roles of prisoner and guard over an 8‐day period, most guards did not automatically adopt an abusive, tyrannical role. Instead, when prisoners developed a strong collective identity, they effectively challenged guard authority—only a small minority (approximately 20–30%) displayed any harsh behaviour before collective resistance led to a power shift. This study suggests that the emergence of oppressive behaviour is not inevitable.
• The Abu Ghraib prison scandal (2003)


  supports Zimbardo’s findings by showing that, in a dehumanising environment with unclear authority, a small percentage of personnel (around 10–20%) engaged in abusive behaviour. Similar to Zimbardo’s study, situational factors like anonymity and lack of oversight played a key role in the abuse. The real-world setting adds ecological validity, suggesting that prison environments can indeed foster extreme behaviours in some individuals, even outside lab settings

  
• Ecological Validity (Negative):

  Zimbardo’s study was conducted in a makeshift prison in the basement of Stanford’s psychology building—a highly artificial setting that fails to capture the full complexity and stressors of an actual prison environment.
• Ethics:

  • Lack of Fully Informed Consent: Participants were not fully informed about the true nature of the experiment, including the potential risks involved in the simulated arrest and imprisonment.
  • Psychological Harm: Several prisoners experienced extreme distress—with five being released early due to severe emotional reactions—highlighting the substantial psychological risk.
  • Deception: The use of staged arrests meant that participants were deliberately misled about the experiment’s purpose, breaching ethical guidelines.
• Ethical counterpoint

  • There were no set ethical guidelines at the time of Zimbardo's study
  • Zimbardo argued the deception improved the "naturalness" of his participants behaviour.
• Demand Characteristics:

  The structured role assignments and explicit cues (such as instructions given to guards) may have signalled to participants what behaviours were expected, thereby influencing their actions and potentially inflating the apparent conformity to roles.

  Some of the volunteers may have tried to be "good subjects" and behaved in the ways they thought Zimbardo wanted.
• Conformity to Roles is Not Automatic:

  Subsequent research, notably the BBC Prison Study by Haslam and Reicher (2006), demonstrated that not all individuals conform automatically; under alternative conditions, many participants resisted abusive role behaviours, indicating that the extreme outcomes observed by Zimbardo are not inevitable.
• Subjectivity

  Zimbardo became too involved in the study, he adopted the role of "prison superintendent" in his own study, and he became trapped in his day-to-day activities of his role.