Humans excel in familiar face recognition, but often find it hard to make identity judgements of unfamiliar faces. Understanding of the factors underlying the substantial benefits of familiarity is at present limited, but the effect is sometimes qualified by the way in which a face is known--for example, personal acquaintance sometimes gives rise…

Matching unfamiliar faces is highly error-prone, and most studies highlight the implications for real-world ID-checking. Here we study a particular instance of ID-checking: proof of age for buying restricted goods such as alcohol. In this case, checkers must establish that an identity document is carried by its legitimate owner (i.e., that the ID…

Research in face recognition has tended to focus on discriminating between individuals, or "telling people apart." It has recently become clear that it is also necessary to understand how images of the same person can vary, or "telling people together." Learning a new face, and tracking its representation as it changes from…

Psychological studies of face recognition have typically ignored within-person variation in appearance, instead emphasising differences "between" individuals. Studies typically assume that a photograph adequately captures a person's appearance, and for that reason most studies use just one, or a small number of photos per person. Here we show that…

We are able to recognise familiar faces easily across large variations in image quality, though our ability to match unfamiliar faces is strikingly poor. Here we ask how the representation of a face changes as we become familiar with it. We use a simple image-averaging technique to derive abstract representations of known faces. Using Principal…