Nicola Bruno, Marco Bertamini

According to surveys of art books and exhibitions, artists prefer poses showing the left side of the face when composing a portrait and the right side when composing a self-portrait. However, it is presently not known whether similar biases can be observed in individuals that lack formal artistic training. We collected self-portraits by naïve photographers who used the iPhone™ front camera, and confirmed a right side bias in this non-artist sample and even when biomechanical constraints would have favored the opposite. This result undermines explanations based on posing conventions due to artistic training or biomechanical factors, and is consistent with the hypothesis that side biases in portraiture and self-portraiture are caused by biologically- determined asymmetries in facial expressiveness.