first impression

In psychology, a first impression is the event when one person first encounters another person and forms a mental image of that person. Impression accuracy varies depending on the observer and the target (person, object, scene, etc.) being observed. First impressions are based on a wide range of characteristics: age, race, culture, language, gender, physical appearance, accent, posture, voice, number of people present, and time allowed to process. The first impressions individuals give to others could greatly influence how they are treated and viewed in many contexts of everyday life.