Many people occasionally fail to recognise a familiar face, or even mistake an unknown person for someone they know. However, individuals with prosopagnosia have a severe face recognition deficit, affecting even the most familiar faces, such as their spouse or children. This failure to recognise familiar faces occurs every day, but many prosopagnosics have developed compensatory strategies to help with person recognition. For example, they might recognise a person by their hairstyle, clothing or gait, or simply because they expect to see a person within a given context. However, if they unexpectedly encounter a familiar person, these compensatory strategies often break down.