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Prosopagnosia Test
This self-report questionnaire, the Twenty-item prosopagnosia index (PI20), assesses the presence and severity of prosopagnosic traits. 

Participation in this test is voluntary and you are able to withdraw at any stage. Your results will be kept confidential, held in a secure encrypted manner, in line with the Data Protection Act 1998. If you have any questions about this task, our research or anything else, feel free to contact us at

Researchers may freely use the PI20 for academic purposes. Please cite the measure as follows:  

Shah, P., Gaule, A., Sowden, S., Bird, G., & Cook, R. (2015). The 20-item prosopagnosia index (PI20): A self-report instrument for identifying developmental prosopagnosia. Royal Society Open Science, 6: 140343.

Please contact the lead author ( before using the PI20 for non-research applications (e.g. on media websites, in healthcare or clinical settings).   

A printable version of the PI20 is also available for free download with guidance on scoring and interpretation. pdf

Thank you for your interest in our research. Due to the volume of responses we receive each day, our current level of funding means we cannot always respond in person. For guidance on scoring and interpretation of the PI20, please see:
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