Abstract Recent studies show that subtle cues of observation affect cooperation even when anonymity is explicitly assured. For instance, recent studies have shown that the presence of eyes increases cooperation on social economic tasks. Here, we tested the effects of cues of observation on trusting behavior in a two-player Trust game and the extent to which these effects are qualified by participants' own attractiveness. Although explicit cues of being observed (i.e., when participants were informed that the other player would see their face) tended to increase trusting behavior, this effect was qualified by the participants' other-rated attractiveness (estimated from third-party ratings of face photographs). Participants' own physical attractiveness was positively correlated with the extent to which they trusted others more when they believed they could be seen than when they believed they could not be seen. This interaction between cues of observation and own attractiveness suggests context dependence of trusting behavior that is sensitive to whether and how others react to one's physical appearance
