Sociocognitive (Atkinson, 2011) and complex dynamic systems approaches (Larsen-Freeman & Cameron, 2008) highlight the inextricable connectedness of social and cognitive phenomena in second language (L2) learning. Previous research found numerous ties between L2 learning and both learners' sociocultural background as well as their affective attitudes such as their Tolerance of Ambiguity (TOA; Ely, 1995; Herman, Stevens, Bird, Mendenhall, & Oddou, 2010). However, there is little insight as to how these social and cognitive factors are interrelated. This article explores the interconnections between socioculturalplace of upbringing, international experience, languages-and cognitive-attitudinal-TOA, Attitudinal and Behavioral Openness (ABOS; Caligiuri, Jacobs, & Farr, 2000)-learner backgrounds among 49 elementary-level students of L2 German at a U.S. university. Correlation analyses show a complex network of learners' sociocognitive backgrounds and suggest that international students tend to have lower TOA and higher ABOS than domestic students. Implications for L2 German teaching are discussed. In their 2016 manifesto, the Douglas Fir Group made the case for a transdisciplinary approach to studying second language acquisition (SLA) by expanding the field's traditional focus on linguistics and psychology. The authors see language learning as follows: Language learning is a complex, ongoing, multifaceted phenomenon that involves the dynamic and variable interplay among a range of individual neurobiological mechanisms and cognitive capacities and L2 learners' diverse experiences in their multilingual worlds occurring over their life spans and along three interrelated levels of social activity: the micro level of social action and interaction, the meso level of sociocultural institutions and communities, and the macro level of ideological structures. (Douglas Fir Group, 2016, p. 36)