I know that the chapter divisions are a Christian invention, and therefore don't exist in very old Jewish sources (Aleppo Codex, Leningrad Codex, dead sea scrolls, etc.). However our divisions don't always agree with the Christian divisions. What are the Jewish sources for these divisions? If we rely for example on various codexes for our text and vowels, what do we rely on to know where to insert chapter breaks?
Just for the record, I have noticed that different printed chumashim differ. For example the chapter breaks in my Koren tanach do not match my Artscholl or Hertz chumash. (This last fact is what has led me to try and find out the answer to this).