Why are muslims so friendly?

I have been hanging around these muslims (middle eastern ones) for a while at school. I would be randomly sitting with my friends(1 is muslim) and other muslims would greet and shake everyones hand and say hello when they pass by us. Even if they don't know you. I found it freaky at first. Because im not use to such politeness in north america. But they are really nice and well mannered compared to other people.