Defining what may be termed an "extreme" culture is a somewhat difficult task. It is obviously a tag that we who fall within the realms of traditional, contemporary, Western society can deem others. Once you deviate really far from the standard, life is radically "different". Yet we are not talking here about individuals, but rather sizable groups who share common interests, yet happen to be in a sense severed from the practices of the dominant society. As we all know, however, these cultures are capable in time of growing to be the norm. For one example: the birth of Christianity. Christians were persecuted for hundreds of years as outsiders who did not have a place in the Roman world. Today, it has spawned numerous religions, and is one of the most dominant belief systems in the world today. The point that interests me most is perspective. Those within the norms of society can classify groups as radical or extreme, yet we are as far removed from their beliefs and practices as they are from us. I think time is the only indicator. Some of what is radical today could very well be the norm tomorrow.

While what you say is true, isn't there any aspect of radical cultures that is related solely to the way in which they practice their beliefs. For example, take the religion of islam and take radical islam. Although they are based on the same core set of beliefs, radical islam is also based on the belief that all who do ot convert to islam should be killed. To me, characteristics like that are what makes a culture radical or extreme. I think that once the idea of all or nothing is introduced into a culture, that culture has everything it needs to be radical or extreme. If you, and the culture you subscribe to, are unwilling to accept that there are differing beliefs and viewpoints, you, and the culture you subscribe to, are most likely, to some degree, extreme or radical.