In Steinbeck's The Pearl, Kino could be considered to be the cause of his own downfall. Had Kino heeded the warnings and advice of his wife, Juana, regarding the Pearl of the World, he would not have found himself in situations that put himself and his family in danger.
Now the tension which had been growing in Juana boiled up to the surface and her lips were thin. "This thing is evil," she cried harshly. "This pearl is like a sin! It will destroy us," and her voice rose shrilly. "Throw it away, Kino. Let us break it between stones. Let us bury it and forget the place. Let us throw it back into the sea. It has brought evil, Kino, my husband, it will destroy us." And in the firelight her lips and her eyes wer alive with her fear.
In addition, Kino was unwilling to accept the offers of those who would have bought the pearl from him. It is true that he was being treated cruelly when not being presented with fair offers for the pearl, but he could have accepted something and been better off than he was.
Kino is responsible for his own demise simply through his own thoughts and actions. First, Kino inadvertently announced that he possessed the "Pearl of the World" to the entire town when he informed his neighbors of his find. This let it be known that it was in his possession, which in turn led to the attacks, murders, and other destruction. Second, he did not listen when his own wife told him to get rid of the pearl by throwing it in the ocean. Third, his own paranoia, guilt, and greed caused him to cast aside his old life and make a run to the city in order to get a higher price for the pearl. His paranoia caused him to believe that there were trackers following him and his family (they may have been animal trackers out on a hunt and been oblivious to Kino's presence). His decision to attack the trackers first inadvertently caused his son to suffer. All of these reasons and examples explain part of the reason of how Kino was responsible for his own demise.