Grammar matters: The tainting effect of grammar usage errors on judgments of competence and character

The human tendency to judge another person's personality traits can be prompted by as little as a snapshot of that person, and such judgments can have consequences for future interactions (Snyder, Tanke, & Berscheid, 1977). We tested the hypothesis that people make judgments about others' personality traits – particularly those desired by employers – on the basis of their written grammar usage. In the study, community adults read a hypothetical job application cover letter and then rated the applicant on a variety of dimensions. Unbeknownst to the participants, there were three cover letters that held the same content but differed in their rate of surface-level grammar usage errors (no errors; an average error rate of 2/100 words; or a high error rate of 4/100 words). Participants who read a letter that contained grammar usage errors downgraded the applicant's writing as well as their standing on personality traits such as capable, hard-working, and team-oriented. The effects were consistent and imply that people should attend to their grammar usage if they want to make a positive first impression. We propose that the effects we documented are due to actual associations between the quality of individuals' grammar competence and their conscientiousness and intelligence.