Scenario: The big cataclysm occurs in 2012, and the vast majority of life is wiped out. Groups of clever people have planned for this and camped out at spots predicted to be safe. And they survive. Life afterwards will have all the social problems of today.

Size of groups?

I was reading New Scientist (20/27 Dec 2003, pages 60-61) - an article about the ideal size of human tribes, clans etc. After studying other primates,

"Dunbar then predicts that humans should have social networks of about 150 people.

Support for this number comes from tribal societies and from history. Modern hunters and gatherers typically live in clans of about 150 members (although they can range from 90 to 200).

....The size of hunter-gatherer groups... is constrained by the amount of territory people can cover and its productivity in terms of food."

The article began by saying that for christmas cards, taking into account that it is common for say a couple to send a card to a family of four, we each typically send Xmas wishes to about 150 people - the ideal size of a social network.

So come 2012, do we prepare in clans of 150, or do we be very practical and ghoulish and have large clans, with the expectation that some might not survive a cataclysm?