Emotional conflict in interpersonal interactions.

Facial displays of emotions can help to infer the mental states of other individuals. However, the expectations we generate on the basis of people's emotions can mismatch their actual behaviour in certain circumstances, which generates conflict. In the present study, we explored the neural mechanisms of emotional conflict during interpersonal interactions. Participants had to accept or reject economic offers made by several partners who displayed emotional expressions. On every trial, a cue informed participants of whether they could trust the emotion of their partner or not. Trustworthy (low-conflict) partners with happy facial expressions were cooperative and those with angry expressions did not cooperate. Untrustworthy (high-conflict) partners, on the other hand, cooperated when their expression was angry and did not cooperate when they displayed a happy emotion. Behavioural responses were faster for trustworthy than for untrustworty partners. High-conflict partners activated the anterior cingulate and the anterior insula. In turn, trustworthy partners were associated with activations in the left precuneus. Our results suggest that the emotion displayed by another person affects our decision-making in social contexts. When emotional expressions are linked to their natural consequences, they engage ToM processes. In contrast, untrustworthy emotional expressions engage conflict-related brain regions.