If there are definite and orderly cultural differences in human face processing, then why have so many autism researchers felt confident in asserting that face processing characteristics that they claim are associated with autism are pathological, rather than merely differences or variations? Just another employment of the idea that anything associated with autism must by definition be pathological and inferior and maladaptive? Sounds like prejudice to me!
A quote from the conclusion of an abstract of one study of face perception:
"These results demonstrate that face processing can no longer be considered as arising from a universal series of perceptual events. The strategy employed to extract visual information from faces differs across cultures."
Caroline Blais, Rachael E. Jack, Christoph Scheepers, Daniel Fiset and Roberto Caldara (2008) Culture Shapes How We Look at Faces.PLoS ONE. 2008; 3(8): e3022. Published online 2008 August 20. doi: 10.1371/journal.pone.0003022
Tan CBY, Stephen ID, Whitehead R, Sheppard E (2012) You Look Familiar: How Malaysian Chinese Recognize Faces. PLoS ONE 7(1): e29714. doi:10.1371/journal.pone.0029714