Sui generis
In sociology, the "sui generis" is what has been externalized, then internalized in the overall public and becomes a part of society that simply exists in its construct. It is not something that is not thought to have been created, because it is imbedded in everyone's way of thinking and being. Instances include the idea of love, or going to school, or clothing belonging to a specific gender. These examples are "sui generis" for they simply exist in society and are widely accepted without thoughts of where they come from or how they were created.
American anthropology
Attention to symbols, the meaning of which depended almost entirely on their historical and social context, appealed to many Boasians. Leslie White asked of cultural things, "What sort of objects are they? Are they physical objects? Mental objects? Both? Metaphors? Symbols? Reifications?" In "Science of Culture" (1949), he concluded that they are objects ""sui generis""; that is, of their own kind. In trying to define that kind, he hit upon a previously unrealized aspect of symbolization, which he called "the symbolate"—an object created by the act of symbolization. He thus defined culture as "symbolates understood in an extra-somatic context."