Prosopagnosia

How it works

Prosopagnosia, or face blindness, is trouble recognising faces, even familiar ones. Other vision and thinking usually work normally¹.

The acquired form follows brain damage⁴. Autopsies and scans nearly always show damage in the fusiform gyrus, on the underside of the brain⁴. The developmental form is lifelong, with no brain injury¹.

Many people with it recognise others by voice, hair, clothing, gait, and context¹⁴. These habits can become so automatic that people with milder cases do not know how poor their face recognition is⁴. Many only find out as adults¹.

It often runs in families¹⁴. In a 2006 study, all 14 people whose families were tested had an affected parent, sibling, or child. The authors said the pattern was consistent with a single dominant gene². At the other end, super-recognisers are about as good at faces as people with the lifelong form are bad⁴.

How common it is

A 2006 German study gave 689 pupils and medical students a questionnaire and an interview. It found 2.47%². It used no face tests, which later researchers criticised³.

A 2023 study gave 3,116 adults a questionnaire and two face tests. Published cut-offs gave rates from 0.13% to 5.42%. The one used most often gave 0.93%. Counting mild cases too gave 3.08%. Poor recognisers formed no separate group, so any cut-off is a choice³.

Try it

1. Open the PI20 questionnaire⁵.
2. Rate each of its 20 statements from 1 (strongly disagree) to 5 (strongly agree). Five items are scored in reverse.
3. Add up the total, from 20 to 100. The page says 65 or more means a good chance of developmental prosopagnosia⁵.

A self-check is not a diagnosis. Most research diagnoses also need low scores on computer face tests³.

Is it a problem?

It depends on how strong it is. It is not a sign of low intelligence¹. Severe cases can mean not recognising your own partner or child⁴. Others may read it as a lack of interest, and it can lead to social anxiety¹.

Mention it to a doctor if your face recognition was normal and then got worse. A new loss can follow a stroke, a head injury, or a disease such as Alzheimer’s¹⁴.

History and culture

The German neurologist Joachim Bodamer named the condition in 1947, from the Greek words for “face” and “not knowing”¹.

The neurologist Oliver Sacks had the lifelong form. At times he did not recognise himself in a mirror⁴. In a 2010 essay he wrote that Jane Goodall had some face blindness, even for chimpanzees, and the painter Chuck Close a severe lifelong form⁴. Face Blind UK is run by and for people with the condition⁶.