https://www.scientificamerican.com/article/new-promise-for-those-who-suffer-from-face-blindness/

Alice is six years old. She struggles to make friends at school and often sits alone in the playground. She loses her parents in the supermarket and approaches strangers at pickup. Once she became separated from her family on a trip to the zoo, and she now has an intense fear of crowded places. Alice has a condition called face blindness, also known as prosopagnosia. This difficulty in recognising facial identity affects 2 percent of the population. Like Alice, most of these people are born with the condition, although a small number acquire face-recognition difficulties after brain injury or illness.

Unfortunately, face blindness seems largely resilient to improvement. Yet a very recent study offers more promising findings: children’s face-recognition skills substantially improved after they played a modified version of the game Guess Who?over a two-week period. In the traditional version of Guess Who?, two players see an array of 24 cartoon faces, and each selects a target. Both then take turns asking yes/no questions about the appearance of their opponent’s chosen face, typically inquiring about eye color, hairstyle and accessories such as hats or spectacles. The players use the answers to eliminate faces in the array; when only one remains, they can guess the identity of their opponent’s character.