The facing bias in biological motion perception: effects of stimulus gender and observer sex

Under orthographic projection, biological motion point-light walkers offer no cues to the order of the dots in depth: Views from the front and from the back result in the very same stimulus. Yet observers show a bias toward seeing a walker facing the viewer (Vanrie, Dekeyser, & Verfaillie, 2004). Recently, we reported that this facing bias strongly depends on the gender of the walker (Brooks et al., 2008). The goal of the present study was, first, to examine the robustness of the effect by testing a much larger subject sample and, second, to investigate whether the effect depends on observer sex. Despite the fact that we found a significant effect of figure gender, we clearly failed to replicate the strong effect observed in the original study. We did, however, observe a significant interaction between figure gender and observer sex.