There is a long-standing debate on the influence of physiological signals on social behavior. Recent studies suggested that heart rate variability (HRV) may be a marker of social cognitive processes. However, this evidence is preliminary and limited to laboratory studies. In this study, 25 participants were assessed with a social cognition battery and asked to wear a wearable device measuring HRV for 6 consecutive days. The results showed that reduced HRV correlated with higher hostility attribution bias. However, no relationship was found between HRV and other social cognitive measures including facial emotion recognition, theory of mind or emotional intelligence. These results suggest that HRV may be linked to specific social cognitive processes requiring online emotional processing, in particular those related to social threat. These findings are discussed in the context of the neurovisceral integration model.