Object-based combat (OBC) (unique to humans) and the human phenotype both feed into the Merge Field of Combat.
The Merge Field of Combat (Merge) is the shared moment of anticipation, which can last indefinitely and remains open before, during, and after combat due to the persistent and wildcard nature of OBC. Here, signals are tried, tested, rejected, accepted, reevaluated, etc., in an effort for all parties to defer violence.
If the signaling process of Merge fails, Violence results. The signals of Violence are then passed to the lexicon (language).
If Merge succeeds, then the signals are Parsed and enter the lexicon.
No matter the outcome of Merge, all signals that come out of Merge carry the infinitely complex, recursive depth of the Merge field, producing grammatical language.
Use of language alters the human phenotype to assist it in the use of language. This might have a domestication effect by inhibiting neural crest cell expression, resulting in white palms, white sclera, bigger brains (?), etc. (all this is conjecture, further study is needed).
It’s possible that Violent language can alter the phenotype as well, having adverse affects on the ability to Parse in the future. So by the same logic, Violent language produces phenotypes which aid in Violence. This is a sort of game played between Violence and Parse.
Presumably, overall, use of language produces phenotypes which assist the individual’s ability to be “read” by antagonists as well as his/her ability to read antagonists. Naturally, phenotypes which aid in the deferral/avoidance of apocalyptic violence are better for humans overall than ones which aid in use of violence, but that doesn’t prevent the phenotype from degrading to the point where apocalyptic warfare could become unavoidable.
Language produces art, other languages, etc. I couch all this under Tech & Innovation.
Tech and innovation are co-opted by the object-based combat (OBC) mechanism, and the cycle repeats.