Can emotion explain the Happiness Superiority Effect for schematic faces in heterogeneous backgrounds?

Recently, D.V. Becker, Anderson, Mortensen, Neufeld, and Neel (2011) proposed recommendations to avoid methodological confounds in visual search studies using emotional photographic faces. These confounds were argued to cause the frequently observed Anger Superiority Effect (ASE), the faster detection of angry than happy expressions, and conceal a true Happiness Superiority Effect (HSE). In Experiment 1, we applied these recommendations for the first time to visual search among schematic faces which had previously yielded a robust ASE. Contrary to the prevailing literature, but consistent with D.V. Becker et al. (2011), we observed a HSE with schematic faces. In an additional experiment, background heterogeneity was isolated as the key determinant leading to the HSE. Finally, we manipulated mood to determine the extent to which the HSE observed in Experiment 1 could be explained by the emotional meaning transmitted by the faces