Figure 1. Performance on (A) the CFPT, (B) the CFMT and (C) a famous faces test.

‘CFPT’ refers to the Cambridge Face Perception Test [38] and ‘CFMT’ to the Cambridge Face Memory Test [48]. ‘Higher IQ’ refers to Möbius participants and aged-matched controls with IQs within the higher range; ‘Older Low-IQ’ refers to the control group matched to MB2 according to age, IQ and gender; and ‘Younger Low-IQ’ refers to the control group matched to MB5 on the same measures.