The influence of partner trustworthiness and relationship closeness on interpersonal trust in individuals with attachment anxiety: An ERP study

Interpersonal trust (IT) is a combination of individuals’ cognitive evaluations of others’ trustworthiness and affective considerations related to the relationships. Individuals’ trust decisions overly relying on the intimacy of the relationship can be detrimental to their socialization. Attachment styles provide a theoretical framework for explaining individual differences in IT and the balance between cognition control and affective evaluation in social-information processing. However, it remains unclear whether high attachment anxiety (AX) individuals with high interpersonal needs exhibit non-socially adaptive trust decisions, characterized by an over-reliance on relationship closeness (RC), independent of partner trustworthiness (PT). A coin-toss task, combined with event-related potential (ERP), was utilized to explore the performance and temporal characteristics of trust decision-making among individuals with high and low AX under the influence of the two factors. The behavioral results showed that high-AX individuals tended to trust close others regardless of their trustworthiness, while low-AX individuals only trusted close others under low-PT conditions, with no differences in RC for high-PT. The ERP results revealed that high-AX individuals exhibited an enhanced positive P1 by low-trust partners, only discerning differences in RC for high-trust partners (more negative N2 by strangers than friends), reflecting poor conflict-detection abilities confronted with low-trust partners. Low-AX individuals’ neural activity showed higher consistency with their behavioral performance, indicating that trust in close others under low-trust conditions was due to the fewer conflicts elicited and higher expectations of them, reflecting smaller N2 and larger P3. Overall, these findings indicated that high-AX individuals’ IT decision-making was primarily influenced by their reliance on affective evaluation in information processing and weaker cognitive-control abilities, highlighting the contribution of attachment to social-information processing.