This may have entailed some combination of cooperation and specialization among group members. Also, it is unlikely that one can overestimate the importance for, and culmulative impact on, all human culture, of the transmission of procedural and declarative knowledge between generations. Perhaps only with the emergence of such relationships did human society have the requisite structure in place to nurture the technological developments of the Late Paleolithic. A third factor, that may have interacted with the cultural factors, may have been significant developments in language. The present argument does not require, however, the assumption that Neanderthals or other, even earlier, hominids were utterly bereft of language.
Language is a collective enterprise.
Language does not exist within the brain alone but equally within cultures. Yet, if they did not develop closely knit family groupings and mentoring relations across generations the long term effects of language were seriously constrained. Human speech is thoroughly dialogical. It is not simply a matter of sending and receiving messages, but of mutually constructing a dialogue within which plans, concepts, and meanings are created, maintained and changed. In dialogue one is constantly challenged to clarify, make explicit, and defend one's utterances.