The own-age bias is one in which people recognize faces of people their own age more accurately than faces of other ages (e.g., Anastasi & Rhodes, 2005, 2006) and appears to be, at least, partially based on experience (Harrison & Hole, 2009). Indeed, Hills and Lewis (2011a) have shown that 8-year-old faces are more accurately recognized by 8-year-old children than by 6- or 11-year-old children, suggesting the own-age bias develops rapidly. The present study explores the own-age bias in a developmental study in participants aged 6–10 years. Ninety participants (divided into 3 groups of 30 on the basis of their age at the first time of testing) undertook a standard old/new recognition paradigm in which their recognition accuracy was measured for 8- and 20-year-old faces. Results showed that when the participants were 8 years old, they recognized 8-year-old faces more accurately than when they were 7 or 9 years old. This effect was found to be based on mechanisms that differ from simple developmental improvement. This is the first study to show the development of the own-age bias in face recognition using a longitudinal design. These results show that the face recognition system is updated on the basis of recent experience and/or motivation to process faces, creating recognition biases.