Red is a signal in the non-human animal world of both danger and sexual receptivity [5], [20], and there is evidence in a variety of species that red coloration serves different functions in different contexts, including mating and competition contexts (for reviews, see [34]–[36]). The current results extend this work to human behavior by revealing parallel effects to those found “in the wild.” Although our research was not designed to test the ultimate origin or distal cause of these red effects [37], we do think that the clear parallels that may be drawn between human and non-human behavior in this regard hint at a biological basis for the effects [8], [38], [39]. Actually, we suspect that the red effects documented herein are a joint function of biologically-based predispositions that are reinforced and extended by social learning (see [8]). Clearly, however, additional research is needed before definitive statements on this matter may be offered (see [40], for a start at such work).