Here's an interesting article describing why "the end is nigh" thinking has evolved from natural selection.
https://www.newscientist.com/article/mg21028156-300-the-end-is-always-nigh-in-the-human-mind/Cognitively, there are several processes at work, starting with the fact that our brains are pattern-seeking belief engines. Consider this evolutionary thought experiment. You are a hominid on the plains of Africa 3 million years ago. You hear a rustle in the grass. Is it just the wind or is it a dangerous predator? If you assume it is a predator but it turns out that it is just the wind, you have made what is called a type I error in cognition, also known as a false positive, or believing something is real when it is not. You connected A, the rustle in the grass, to B, a dangerous predator, but no harm. On the other hand, if you assume that the rustle in the grass is just the wind but it turns out that it is a dangerous predator, you have made a type II error in cognition, also known as a false negative, or believing something is not real when it is. You failed to connect A to B, and in this case you’re lunch.
The problem is that assessing the difference between a type I and type II error is highly problematic in the split second that often determined the difference between life and death in our ancestral environments, so the default position is to assume that all patterns are real; in other words, assume that all rustles in the grass are predators. Thus, there was a natural selection for the cognitive process of assuming that all patterns are real.