Collectivism
This term has been covered by the website Wikipedia as "Collectivism"
This mediawiki site, a `wiki dictionary` about the nature and practice of free improvisation declines to duplicate that listing. Below there is an introduction - a simple copy and paste. from Wikipedia then a link to the Wikipedia entry.
Introduction, copied from Wikipedia
Collectivism is a value that is characterized by emphasis on cohesiveness among individuals and prioritization of the group over the self. Individuals or groups that subscribe to a collectivist worldview tend to find common values and goals as particularly salient[1] and demonstrate greater orientation toward in-group than toward out-group.[2] The term "in-group" is thought to be more diffusely defined for collectivist individuals to include societal units ranging from the nuclear family to a religious or racial/ethnic group.[3][4]
Link to the Wikipedia page
https://en.wikipedia.org/wiki/Collectivism