Attribution of Selfhood Based on Simple Behavioral Cues: Toward a Pars-Pro-Toto Account.

While the necessity of a concept of "self" for understanding human behavior remains subject to debate, it evidently has significance in everyday life: Lay individuals ascribe selves to humans but also to animals and technical systems, shaping their interactions accordingly. The literature suggests that there are distal behavioral cues eliciting this perception of selfhood and they may be as minimal as simple movement observed as causal. We aimed to identify which types of behavioral cues increase selfhood-attribution to other agents such as robots. Specifically, we compared behavior of nonhumanoid robots suggesting either the presence or absence of behavioral cues for one of the characteristics of causality, equifinality, behavioral efficiency, learning sensitivity, and context sensitivity. Results showed a consistent pattern of increased selfhood-attribution toward robots exhibiting any one of the examined minimal characteristics. Furthermore, most perceived sentient characteristics of the robot were triggered by any single characteristic's cue. These results reflect a Halo effect like pattern: Even a single perceived cue of selfhood-related characteristics may be sufficient to trigger a change in overall selfhood-attribution to robots. We suggest two versions of a Brunswikian model of selfhood-judgment, wherein selfhood is attributed based on the perception of (probably loosely defined) self-related characteristics. We propose that not all characteristics are directly perceived by their corresponding behavioral cues; rather, that the characteristics interact with each other and/or distal cues trigger the perception of more than one characteristic. We term this a Pars-Pro-Toto account as people go way beyond the perceived information when attributing selfhood.