What is perception?
Every one have a different mind of every thing like humains, photos, objects, etc...
There is three things that is bad for your perception the first is parents: they always telling you black man is bad white man is good and it's very wrong.
Second is the media: media is like tv, books, internet, etc... they are wrong whene they are tellin you that the islam is a bad religion or whene they are telling that every one have a beard so he is a killer or bad, and the last is your enviorment: always your enviorment have bad humains that get your mind very bad to something or someone.
And to defeat all those bad things is your education if you are ediucated good from your school, your parents ( some times parents are not very educated ) you can be open minded and defeat all bad mind about everyone or everything.