The people have so low IQ that the monkey should have won like almost immediately after they learned how to shoot a gun. They get surprised how monkeys can communicate but the people can't do the same with words. And holy shit, the author really needed to have a kid with no survival instincts. The girl had to be kind to a monkey that basically destroyed their village because she has to be stupid to make drama for the story. Can't fucking justify it being a child monkey if it's in the village where the monkeys attacked you already.