The men come upon young Jack on the verge of destroying an innocent turtle. What is Jack's issue with the turtle, and what does that tell you about Jack's personality?

Jack has been told by a preacher on the ship that in the land of Damascus, a turtle will sing. It is unclear why the preacher would say such a thing, but Jack stares at the turtle for over an hour and becomes frustrated by the lack of sound. Jack is either a bit simple or very easily led.