## 2 Theoretical Background and Hypotheses Development
### Organism (O): Human-Social Robot Relationships  
#### 2.4.1 Parasocial Interaction with MOCCA (PSI)  
Parasocial interaction is defined as a one-sided relationship in which an individual feels emotionally connected to media figures, such as celebrities, social media influencers, or even virtual agents and social robots, without any form of reciprocity [59]. In this form of interaction, individuals feel a sense of emotional engagement with the media figure. Although there is no actual exchange, the individual may experience an illusory sense of two-way human-to-human interaction, feeling as though they are part of a reciprocal relationship [38]. Previous research has shown that individuals engaged in parasocial relationships typically experience a sense of rapport and even reciprocity with their counterparts [59], which, in the long run, becomes the foundation of an illusory interpersonal relationship such as friendship or intimacy. Despite being inherently one-sided, this type of relationship is defined as parasocial [60]. The formation of such relationships is influenced by the perceived credibility, realism, and authenticity of the counterpart [38; 61]. When the counterpart is non-human, its perception of realism and authenticity is heightened if it appears humanlike or is anthropomorphized. Once a non-human counterpart is perceived as possessing human characteristics, individuals are more likely to engage in interpersonal social interactions and form parasocial relationships with it [62]. The more humanlike the counterpart appears, the more real and tangible it seems, shifting users' perception from fictional or artificial to authentic and present [63; 64]. For humanlike social robots like MOCCA, parasocial interaction is facilitated as users begin to view the robot as a conversational partner with whom they feel comfortable sharing personal information. Although MOCCA does not genuinely reciprocate, users may feel emotionally and cognitively involved in a perceived two-way exchange [65]. While parasocial interaction is modeled as a unidirectional outcome of stimulus variables, it fundamentally reflects the user's perception of a reciprocal exchange. Over time, such interactions may develop into deeper bonds [66; 67], where users perceive MOCCA as a real friend, peer, or even a family member. As MOCCA exhibits human-like features, users may attribute moral agency to it, evaluating its actions through human ethical frameworks [48]. When MOCCA's behaviors meet moral expectations, users are more likely to perceive it as a trustworthy partner, facilitating the illusion of a reciprocal relationship [61]. Prior research suggests that moral behaviors cause positive affective responses, strengthening the perceived authenticity of the interaction [68; 69]. However, despite users' emotional engagement with MOCCA, concerns about the potential misuse or leakage of personal information may create psychological barriers that hinder the development of deeper parasocial bonds. Privacy concerns may lead users to limit the degree of openness and emotional sharing with the robot [12]. Social robots rely on pre-programmed algorithms and external inputs to perform tasks, and their perceived autonomy plays a crucial role in shaping users' social perceptions. In HRI, autonomy is a key factor that enhances the robot's perceived social presence and agency [22; 70]. When users perceive MOCCA as highly dependent on rigid, predetermined programming, it diminishes the illusion of autonomy and self-directed behavior. This perception can weaken the authenticity of the interaction, making it harder for users to form emotional attachments, as parasocial relationships often rely on the belief that the counterpart possesses independent agency [71].