Since Darwin’s seminal works, the universality of facial expressions of emotion has remained one of the longest standing debates in the biological and social sciences. Here, we refute this assumed universality. Using a unique computer graphics platform that combines generative grammars with visual perception, we accessed the mind’s eye of 30 Western and Eastern culture individuals and reconstructed their mental representations of the six basic facial expressions of emotion. Crosscultural comparisons of the mental representations challenge universality on two separate counts. By refuting the long-standing universality hypothesis, our data highlight the powerful influence of culture on shaping basic behaviors once considered biologically hardwired. Consequently, our data open a unique nature-nurture debate across broadfields from evolutionary psychology and social neuroscience to social networking via digital avatars.