George Foster (1965) argued that peasant societies often held a worldview characterized by "limited good."
All things are understood to existed in limited quantities. (Foster included love, luck, etc.). Thus, life is a zero sum game: one person's gain is another's loss.
If you believe this, how are you likely to behave?
Next: American Worldviews
The fact that most peasant communities were small is important here. Everyone knew everyone else. People both loved and feared their neighbors. Since you depended on your neighbors for almost everything, good relationships and solidarity with them were vital. The image of limited good makes this problematic. If one person is suddenly better off than others, the others are likely to conclude that the only reason one person could have become better off was by taking things away from other people. One key way that people might be thought to do this is by magic, sorcery, or outright thievery. Being accused of any of these things would present deep difficulties. So, to avoid being accused, people who are successful in one way or another are likely to hide these successes.