Yeah. This is related to supernatural beliefs. If the grass moves it might just be a gust of wind, or it might be a snake. Even if snakes are rare, it's better to be safe than sorry. But, that eventually leads to assuming that the drought is the result of an angry god, and not just some random natural phenomenon.

So, brains are hard-wired to look for causes, even inventing supernatural causes, because it helps avoid snakes.