Social avoidance behaviour modulates automatic avoidance actions to social reward-threat conflict.

Social avoidance behaviour (SAB) significantly interferes with social engagement and characterises various psychopathologies. Dual-process models propose that social behaviour is directed in part by automatic action tendencies to approach or avoid social stimuli. For example, happy facial expressions often elicit automatic approach actions, whereas angry facial expressions often elicit automatic avoidance actions. When motivation to approach avoid co-occurs, automatic action tendencies may be uniquely modulated to direct social behaviour. Although research has examined how psychopathology modulates automatic action tendencies, no research has examined how SAB modulates automatic action tendencies. To address this issue, one hundred and three adults (65 females, 20.72 ± 5.06 years) completed a modified approach-avoidance task (AAT) with ambiguous facial stimuli that parametrically varied in social reward (e.g. 50%), social threat (e.g. 50%), or social reward-threat conflict (e.g. 50%/50%). SAB was not associated with automatic actions to any single parametric variation of social reward and/or social threat. Instead, SAB was associated with a quadratic (i.e. U-shaped) pattern in which automatic avoidance actions to social reward-threat conflict were faster to unambiguous social reward and social threat. Moreover, this association was independent of internalizing and social anxiety symptoms. These results provide insight into mechanisms underlying SAB, which offers clinical implications.