As information technology (IT) has become an indispensable part of people’s everyday lives (Yoo, 2010), being human is more than ever influenced by IT. Thereby, a growing psychological – often subconscious - intertwinement between human beings’ social roles and relationships and their interactions with IT can be observed (Carter and Grover, 2015). For example, human beings use IT to understand, expand, or represent their self (c.f., Carter and Grover, 2015), determine online who they are, and evaluate their self-worth (e.g., Wenninger et al., 2019; Yang et al., 2018), strive in online environments for belonging and meaningful existence (Baumeister and Leary, 1995; Bernstein, 2016), and internalize IT as part of their identity (Carter et al., 2020a; Carter et al., 2020b). As human beings are essentially social beings (Riva and Eck, 2016), those social processes are essential for individuals to cope with a complex social world. Moreover, they relate to an individual’s psychological and physiological well-being. Information systems (IS) research that examine the intertwinement between human beings’ socio-psychological nature and IT use behavior indicates a reciprocal relationship between so-called digital users and IT. For example, socio-psychological concepts like emotional attachment, relatedness, and dependency (i.e., IT identity) determine IT use behavior (Carter and Grover, 2015), expanding traditional technology acceptance research and offering a new lens to understand individuals’ IT use behavior (Venkatesh et al., 2003; Venkatesh et al., 2012; Ven-katesh et al., 2016). Moreover, IS research suggests that due to growing opportunities to interact with others and enabled by IT’s functionalities, IT use triggers physiological and psychological reactions, ranging from severe consequences (e.g., depression, anxiety, bipolar mania) to individuals who report higher life satisfaction due to the ability for social participation in online environments (e.g., Verduyn et al., 2017; Krasnova et al., 2015). Building on first investigations and in light of the increasing integration of IT into human beings’ everyday life, IS research calls for (1) the integration of socio-psychological perspectives in IS research to understand better and predict individuals IT use behavior and (2) insights on new outcomes of technology use like subsequent thoughts, physiological, and emotional reactions within socio-technical contexts (Carter and Grover, 2015; Venkatesh et al., 2016). Accordingly, this thesis replies to this calls by following the overarching research objective to enhance the understanding of the reciprocal relationship of how IT use influences one as a hu-man being and how being human influences IT use. This thesis takes on a Service-Dominant-Logic (SDL) perspective by understanding that a digital user’s value perception of IT goes beyond the mere fulfillment of tasks and reflects deeper basic human needs and values in everyday life (Vargo and Lusch, 2004, 2008, 2016; Yoo, 2010). Moreover, this thesis integrates socio-psychological perspectives (e.g., Social Comparison Theory, Social Identity Theory, Temporal Need Threat Model) and established theories from IS research (e.g., Uni-fied Theory on Acceptance and Use of Technology) to explain individuals’ use behavior, social processes when using IT, and self-concept related consequences of IT use. Overall, the thesis encompasses seven research articles. Three research articles enhance the context-dependent understanding of technology acceptance from the perspective of a digital user by providing theoretical explanations for use intentions and actual use of IT regarding new types of IT used in new contexts, new forms of use behavior, and new antecedents that (indirectly) predict IT use behavior. Furthermore, three research articles enhance the understanding of why and how IT use influences self-concept-related aspects of a digital user by providing empirical evidence that digital users utilize IT to determine their self-concept in digital environments. Thereby, digital users make digitally mediated experiences through its functionalities (e.g., paralingual digital affordances, editability, asynchronicity). Which enable and trigger socio-psychological processes and relate to users’ self. Moreover, one article enhances the understanding of IT identity’s role in integrating technology acceptance and a digital user. In this regard, this thesis provides empirical evidence that individuals perceive IT as part of their self. Furthermore, the results indicate that users’ IT identity significantly mediates use behavior. Overall, this thesis contributes to IS research by thoroughly investigating the human-IT relationship. By putting the individual in the center of interest, the thesis proposes further research on digital users’ intentions and actual use of IT, investi-gations of why and how social-psychological processes extend into the online world, and the mediating role of one’s self on context-dependent technology acceptance factors and use behavior.