Chance neglect in performance judgments

Area of Science:

• Cognitive psychology
• Decision science
• Sociology of technology

Background:

• Humans frequently misinterpret or disregard chance information when assessing performance.
• This cognitive bias impacts judgments about the effectiveness of various practices, particularly technological ones.

Purpose of the Study:

• To investigate the systematic misperception or neglect of chance information in performance evaluations.
• To examine how individuals use or fail to use chance-level success rates as a baseline for judging technological efficacy.

Main Methods:

• Conducted studies with diverse samples in China and the United States (N=1387).
• Utilized scenarios with objectively known chance performance rates (e.g., ~50% for fetal sex prediction).
• Analyzed participant underestimation of random guessing success and failure to use chance as a baseline.

Main Results:

• Many participants underestimated the success rate of random guessing.
• Even when aware of chance levels, participants often failed to use this information as a baseline for evaluating expert predictions.
• Chance neglect was more pronounced in performance-related judgments.

Conclusions:

• A significant cognitive bias, termed 'chance neglect,' systematically affects performance evaluations.
• This bias contributes to the underestimation of random performance and the overestimation of specific practices.
• Chance neglect may explain the persistence of ineffective technologies across different societies.