Several lines of evidence point towards a functional role of adaptation in face perception. Face adaptation is reduced in populations with impaired face recognition (Fiorentini, Gray, Rhodes, Jeffery, & Pellicano,
2012; Palermo, Rivolta, Wilson, & Jeffery,
2011; Pellicano, Jeffery, Burr, & Rhodes,
2007; Pellicano, Rhodes, & Calder,
2013). In typical populations, individual differences in face recognition ability are positively correlated with the magnitude of aftereffects induced by face adaptation (Dennett, McKone, Edwards, & Susilo,
2012; Rhodes, Jeffery, Taylor, Hayward, & Ewing,
2014). Finally, face discrimination can be more accurate around an average than a nonaverage face (Armann, Jeffery, Calder, & Rhodes,
2011; Wilson, Loffler, & Wilkinson,
2002), suggesting that calibrating one's perceptual norm to the population average facilitates discrimination (Rhodes, Watson, Jeffery, & Clifford,
2010).