Okay, we have totally dumped the illogical theories on cultural change within groups and accepted without reservation "The world according to Jack" where: problems/desires>resources>solutions>stability/satisfaction.
So why or how does group size influence changes in culture?
Group size is pretty important. Anthropological theory tells us that the smaller the group the less likely it is to have personal property issues. Small groups, what Anthropologists call "bands", have very few personal property issues and typically don't think of owning property in the same way that individuals in larger "tribes" do.
I believe this is based on personal relationships between members of groups. Without getting too deep into the relationships individuals have within and between various cultural sub-groups the basic idea is that people believe more in other people than they do in ideas.
Aristarchus developed the heliocentric theory of the universe about 600 years before Christianity actually became a fully organized religion. His theories were discounted because people believed in Aristotle and his geocentric theories.
This belief in people spreads. As individuals we tend to accept people who are accepted by people we "know". If someone we have a positive relationship with, someone we believe in, accepts a person or their theories we will typically accept that person.
The fewer people who believe in a person the less likely their beliefs are to be accepted by the group.
In this case the problem is interpersonal trust and typically we place our trust in people we believe in. That interpersonal trust relationship is extended from the trust we place in one person to the trust that person places in another person.
If we trust our government and our government tells us that we have to kill Osama Bin Laden to be safe then we all cream for joy when we kill Osama Bin Laden.
Is that good or bad? Does killing a leader whose tactics we understand actually make us safer? Will that leader be replaced with another leader whose tactics and strategy we won't understand?
There are no perfect answers to this or similar questions. There is no "truth" here, just some answers that some people trust more than others.
Some people wanted Osama Bin Laden dead in revenge for 9-11. Some people feel safer now that OBL is dead. Others are angry that the intent of the United States laws against the specific targeting of individual national leaders was broke. OBL was a cultural leader but OBL was not a leader of a country recognized by the United Nations. The intent of the law against targeting specific individual cultural leaders for assassination was to encourage diplomatic solutions.
Cultural groups exist with or without recognition or permission. At the beginning of the genocide of Native Americans their cultural groups were not recognized. When those groups were larger than the invading groups diplomatic solutions were worked out. As the invading groups increased in size the diplomatic solutions were ignored and cultural values were imposed.
Personally I find a great deal of similarity between the killing Native Americans who opposed the United States and the killing of specific cultural or political groups who currently oppose the United States. Both groups expected different behaviors from the United States and both groups reacted violently when those expectations were not met. Both groups developed a lack of trust in the U.S. when the U.S. did not behave as expected.
All of these conflicts revolve around personal trust issues. Those personal trust issues extend into trust of leadership, trust in the leaders of leaders and so on.
As group size increases individuals within the group have reduced trust relationships. This causes smaller sub groups to form where people within these sub groups have stronger trust relationships. These groups form trust relationships with other groups.
Individuals can belong to as many or as few trust groups as they can.
The more rigid the expectations a group has concerning its individual members the more exclusive the group will be. The less rigid the expectations of the group the more inclusive the group will be.
The lines between individual and group psychology and the anthropology of these small cultural sub groups blur at this point. Some will believe that the two disciplines complement each other and some will believe that they have opposing ideologies or goals.
In any case I believe that it is the individual trust issues extended into group trust issues that define the trust issues between various cultural and sub-cultural groups.
Trust is based on expectations. We all have different expectations. When a person or group or thing behaves as we expect we increase trust. When a person or group or thing does not behave in the way which we expect them to our level of trust decreases.
Sometimes we cannot even specifically define our expectations. We only know that our expectations have either been met or not.
In the 'World According to Jack', trust grows out of expectations and trust is transfered from one entity to another.
Trust and expectations become the basis of most of the inter cultural issues we face in cultural groups. The remaining issues are related primarily to ecological conditions such as climate and the condition or availability of natural resources.
Those issues are addressed by applying the available resources, primarily human resources, to the issue.