Thats not a good testimony for the intelligence of the average Westerner.
Actually, if you read Indian history, you realise that tolerance was absolutely essential for survival. The number of invasions that India suffered, without tolerance we would have perished. It was either fight every new group of people that was attracted by the (then) riches of the country or invite them to have the freedom to practise their religion, language, culture etc. without any restrictions. The latter worked so well that we have over 200 languages and around a few thousand dialects, and an eclectic mixture of religions architecture food clothing ideas political affiliations (some states are communist, some states socialist, some fundamentalist) and we all rub along somehow or the other.
So yes, it is possible for different groups to learn to get along. But they all should want to and all should be willing to accept that people can have different beliefs without the necessity to prove any one belief superior over the other.
The "outsider" is only an outsider if you consider him as such. If you can just remember that he too belongs to the human race, he's not an outsider anymore, just another family member you may not agree with but can still meet and chat with on occasion and surprise! he may not be so bad after all!