Should one judge a person by external appearances?

Some people judge a person only by his or her external appearances. I disagree with their attitude. I think that one should never judge a person by external appearances. 

Judging a person by his or her external appearances may mislead your understanding him or her. A person who has a pretty face and wears beautiful clothes may not have same kind of heart inside. On the other hand, the internal characters of a person cannot be judged by his or her external appearances. 

If you judge a person only by his or her external appearances, you may lose chances to make good friends. Everyone has his own habits to choose clothes, hair style and the way to live. Maybe both of you have interests and hobbies in common. You cannot know this point because your wrong judgment from his different ways to deal with something prevents you from knowing his interest and keeps you too far from him to make good friends. 

Judging a person by external appearances is unfair and one-sided. To evaluate a person fairly, you have to know his family, his situation and him entirely and clearly. A person who is from poor family may be intelligent and diligent. The one who can afford expensive clothes may be indifferent with others. 

So I think that judging a person by his or her external appearances always leads us to draw a wrong conclusion about a person. It is limiting and unfair. Everyone longs for the understanding from others. So we should give others chances to show all of their characters and at the same time we should evaluate them fairly and objectively.