A currently popular idea is that all cultures are equal. This arises from a misguided attempt to show respect for and provide dignity to those who come from other than the dominant culture, though it only serves to further disempower them. The culture that a group of people develops in a particular environment is an adaptation to that environment and as such has been molded by the forces present to allow the individuals to effectively operate in that environment. Those from a different environment who have been shaped by a different culture will likely not be as effective in the new environment unless they adapt to its culture. To encourage them not to adapt to the culture or even to advise them to mix in equal proportions their prior culture with the culture of this new environment is doing them a disservice.
The exception to this is when the newcomers from the different culture are able to achieve dominance through force or technological superiority. Then they may provide pressure for structures and patterns in the culture of their new home to conform to their alien culture, and individuals in their new home may be required to adapt to the alien culture. Also, note that some cultures have relatively more universal attributes that empower the individuals who absorb them to dominate others in other environments (e.g., a preference for the scientific method), so these cultures more often become expansive.
On another related point, it is often said that “Politics is downstream from culture.” While not disputing that, I think a more complete representation would be an Escher-like endless loop constructed as follows:
(1) Politics is downstream from culture;
(2) Culture is downstream from both technological innovation and law;
(3) Technological innovation and law are downstream from economic policies;
(4) Economic policies are downstream from politics. (Loop back to (1))