Person vs. Self: Mr. White struggles with his own desires and whether or not to use the monkey's paw. He knows that it is dangerous, but he is also tempted by the possibility of getting what he wants.
Person vs. Fate: The Whites are also struggling against fate. They have been given the opportunity to change their lives, but they must also deal with the consequences of their actions.
Person vs. Society: The Whites are also outsiders in their society. They are poor and do not have the same opportunities as others. This makes them feel even more powerless against fate.