The first impression is the last impression.
I'm sure we've all manifested this saying at least once without really thinking about it. Whether it be the person's clothes, hairstyle, body gesture, behavior at a specific moment, or really any attribute that is viewable with the naked eye, we tend to be quick to group people towards particular characteristics based on that information.
Of course, we have all heard about the importance of a first impression. Whether it be interviews or blind dates, a positive and memorable first impression sets the tone in the relationship that you will have with the other involved person. From a scientific standpoint, studies show that the first memory of whatever holds superiority over the instances that follow, even if they conflict with the first one. As such, that initial experience will then largely dictate the opinions on the subject.
However, when it comes to interviews or dates, many more variables are involved in the first impression than just the meeting or appointment. For your interviewer, he/she has access to your resume, past achievements, professional skills, and much more, and your partner has insight into your general personality, your interests, etc. As a result, the interviewer/partner makes an evaluation and decision that is the most justified one based on everything about you and not just based on that one interview or that one awkward rendezvous.
And it is this aspect that differentiates the difference of the first impression in a fixed, structured setting versus an open and social one: We do not have the necessary information, quantitative and qualitative, to make any real accurate judgment and assessment of new people. From personal experience and talking to friends and acquaintances, what we tend to do with first impressions has grown into an unhealthy habit for many.
While there is no direct solution to this prominent problem, I believe one way we could mediate it is by thinking and reflecting a very old, familiar, and simple saying and its message, "Never judge a book by its cover." The value a book brings to you is not what the cover presents, but rather the contents of the book and the more profound, enriched messages hidden inside.
Of course, there is the potential that your first hitch on someone was correct after all, or that the person is not worth your time after spending enough time to make such a decision. But how can you ever know without even dedicating the conscious effort to discover who that person genuinely is?