Abstract
Affective facial expressions elicit approach-avoidance motivational responses that shape social behavior. Qualitatively, individuals report frequently experiencing competing motivations to approach and avoid other individuals in social contexts (i.e. social approach-avoidance conflict; AAC). Moreover, theoretical frameworks propose that successful navigation of social AAC plays a critical role in adaptive social behavior. However, despite an extensive array of well-validated,
AAC paradigms, no research has developed a paradigm that experimentally elicits and reliably quantifies social AAC in humans. To address this issue, we developed and validated a novel social AAC (SAAC) paradigm with an independent replication across two samples. In the SAAC paradigm, morphed facial expressions are used to parametrically modulate the intensity of social reward (happiness), social threat (anger), or social reward-threat conflict (co-occurring happiness and anger). Demonstrating robust AAC effects, social reward-threat conflict uniquely elicited more intermediate approach-avoidance choice selection and slower reaction times compared to social reward and social threat. Furthermore, computational drift diffusion models demonstrated that social AAC was driven by noisier evidence accumulation processes. Together, these findings demonstrated and replicated that our novel SAAC paradigm reliably elicits social AAC, which may provide a more mechanistic understanding of social behavior and its dysregulation in psychopathology.