The double-edged sword of informality: How informal communication shapes closeness and trustworthiness in personal and professional relationships

Communication style is critical in fostering and maintaining trust in private and professional relationships. Anecdotal evidence and applied communication strategies suggest that an informal communication style not only reflects but also causes feelings of closeness and trust. However, the experimental evidence on this is mixed, which suggests that the effects are contingent on boundary conditions. In the present article, we test four hypotheses about when and why informal communication in private and professional contexts increases or decreases the recipient’s perceptions of the sender’s trustworthiness in three important domains: ability, benevolence, and integrity. Across three experimental studies ( N total = 1085), we find that (1) informality increases perceived sender benevolence both in private and in professional contexts, but that (2) informality reduces perceived sender ability in professional contexts, particularly when it violates formal communication expectations. The results further suggest that (3) informality increases perceived sender benevolence through communicating feelings of closeness and (4) informality decreases perceived sender ability in high-status professional roles through communicating a lack of role awareness. The effect of informality on perceived integrity was moderated by context. Integrity perceptions were decreased in professional but increased in private contexts after informality. These findings highlight the nuanced role of communication context and role expectations in determining the impact of informal communication on trustworthiness perceptions.