Prosopagnosia, often called face blindness, is a difficulty recognizing people's identities from their faces. A person may rely more heavily on voice, hairstyle, clothing, gait, location, or context, and may struggle when those cues change or when somebody appears somewhere unexpected.
Recognizing who a person is and interpreting their facial expression are different skills. Someone may find one difficult without having the same difficulty with the other. Face recognition difficulties can also affect social confidence, following films, recognizing colleagues or relatives, and avoiding accidental offence.
The PI20 is a validated self-report measure developed by Punit Shah, Anne Gaule, Sophie Sowden, Geoffrey Bird and Richard Cook. It describes lifelong developmental face-recognition experiences; it does not by itself diagnose prosopagnosia.
Test Your Face Memory and Contribute to Science
The PI20 records your everyday experience. For an objective image-based measure, adults aged 18 or over can also take Birkbeck, University of London's external Cambridge Face Memory Test. It takes about 20 minutes and contributes data to an active research project.
The external test asks for research consent, uses cookies, stores study information under Birkbeck's data-protection arrangements, and is not optimized for phones or tablets.
How to Answer
Choose how strongly you agree or disagree with each statement based on your usual face-recognition experiences. Answer all 20 statements.
Your answers stay in your browser and are not stored by Autistic Empire.
PI20 Prosopagnosia Assessment
Your Result
PI20 Total Score
What the Score Means
The total ranges from 20 to 100. The PI20 authors describe scores of 65-74 as broadly indicative of mild developmental prosopagnosia, 75-84 as moderate, and 85-100 as severe.
These are research-based indicative bands, not a stand-alone diagnosis. The authors recommend combining self-report with objective face-recognition testing. A result can also be discussed with a neuropsychologist, neurologist, optometrist, or another appropriately qualified clinician depending on your circumstances.
Take the Objective Research Test
The external Birkbeck Cambridge Face Memory Test measures your ability to learn and recognize unfamiliar faces. By taking it, eligible adults contribute to face-memory research as well as receiving an objective task alongside this self-report score.
Developers, Source and Permission
Shah P, Gaule A, Sowden S, Bird G, Cook R. The 20-item prosopagnosia index (PI20): a self-report instrument for identifying developmental prosopagnosia. Royal Society Open Science. 2015;2:140343.
The paper and instrument are published under the Creative Commons Attribution 4.0 licence, permitting reuse with attribution.