I think Jacob might prove to be a child, not unlike Walt. Fits my long-standing theory that the younger you are the better you can control the power of the Island (or draw upon it).
That's why Jack would have eventually found compassion for him?

Or as usual I'm way off base.

__________________
"The Naked Gun!"

Frank Drebin remembers a lost love.

Frank: It's the same old story. Boy finds girl, boy loses girl, girl finds boy, boy forgets girl, boy remembers girl, girls dies in a tragic blimp accident over the Orange Bowl on New Year's Day.

Jane: Goodyear?

Frank: No, the worst.