Do first impression last?

This week we'll be discussing some dilemmas around looks: If most of our communication is non-verbal, then looks matter a lot. But we're advised not to put too much emphasis on looks. Secondly, it is said that beauty is in the beholder's eye, in which case first impressions would have different effects on different people. And coming to first impressions, some people claim that you can assess a lot of character traits of another person accurately only within one-tenth of a second of first meeting them. Yet, do these traits stand the test of time?