I really believe that xenophobia is built into our human psyche, For this is the way humans have protected themselves over the generations. For if you saw a group of blonde men come over the horizon and you were dark haired you would immediately go for your weapons so we have learnt to avoid the unknown.
As children have a fear of strangers
The victims must themselves prove that they are compatible with the group they want to join. Like us all no matter what group we want to join, we all must prove ourselves, for its no good trying to join a swiming group if you cannot swim or a choir if you cannot sing.
So everybody must be able the prove that he/she have something they can give to the group they went to join or that they are compatible to it.
Only if the campaigns, discussions etc, show the person that wants join a group that they can in some way to give /add to the group they want to join and will be compatible to it .