Memorability Is Consistent Across People
Face memorability, whether a particular face is remembered after brief exposure, is surprisingly consistent across different observers. Studies using large sets of face images find that inter-observer agreement on which faces are memorable and which are forgettable is high (r > 0.7), suggesting that memorability is a property of the face itself, not just the observer.
This consistency implies that memorability reflects stable, objective characteristics of face images that all observers process similarly. It is not random and not primarily driven by personal association.
What Makes Faces Memorable
Distinctiveness is the strongest predictor of face memorability. Faces that deviate from the population average, in eye size, nose shape, overall proportions, or other dimensions, are more memorable because they violate the expected configuration more strongly. The unusual face leaves a stronger memory trace precisely because it requires more processing effort to accommodate.
The averageness-memorability relationship is the inverse of the averageness-attractiveness relationship: average faces are more attractive but less memorable; distinctive faces are less conventionally attractive but more memorable. This trade-off reflects different evolutionary pressures on two separate cognitive functions.
Memorability and Face Matching
In terms of celebrity matching, memorable (distinctive) celebrities tend to appear in fewer people's results, they occupy peripheral regions of embedding space and only match faces with genuinely similar distinctive proportions. Forgettable (average) celebrities appear more frequently, as their central embedding position makes them close to more people.
A match with a highly distinctive celebrity is typically a strong, visually obvious resemblance. A match with a more average-featured celebrity may reflect central embedding position as much as specific feature similarity.