Man's Genesis*
This D.W. Griffith movie was released on July 11, 1912. It's a caveman story filmed on California's Santa Catalina Island that starts off with the theme "might makes right" and then evolves into "but brains are better." Two cavemen love the same woman (actress Mae Marsh), and it seems like the one named "Bruteforce" will win the love contest against his rival named "Weakhands" – until, wait for it – Weakhands invents the stone hammer and overcomes Bruteforce.
*You can find a shortened version on Youtube and see what you think, but it did get some good reviews at the time, such as this one: "A most remarkable picture, and one which should create some stir. It is an effort to supply the 'missing link,' and it is a consummately clever effort." – Bioscope (London, England), July 18, 1912