There is a large literature on the own race bias, the finding that people are better at recognizing faces of people from their own race. Here an own gender bias is shown: Males are better at identifying male faces than female faces and females are better at identifying female faces than male faces. Encoding a person's hair is shown to account for approximately half of the own gender bias when measured using hit and false alarm rates. Remember/know judgements and confidence measures are taken. Encoding a person's hair is critical for having a "remember" recollective experience. Parallels with the own race bias and implications for eyewitness testimony are discussed.