The purpose of the personality test in the UPSC Mains is to evaluate a candidate's suitability for civil services, focusing on their values, attitudes, and overall personality traits. This test assesses candidates' abilities to handle public service challenges and their interactions with diverse populations. It helps identify candidates who can demonstrate leadership, empathy, and decision-making skills, essential for effective governance. Overall, the personality test complements the written exams by revealing a more rounded view of the candidates beyond their academic performance.