For centuries mankind has predicted the cataclysmic end of Earth. What does this say about the psychological nature of humanity?

Apocalyptic beliefs are not universal. Hindus, for example, believe that the world is created, destroyed, and reborn in endless cycles spanning billions of years.

To build on what @IchtheosaurusRex said, cultures that have doomsday/end of the world scenarios as part of their mythos are those that view the world in a linear fashion, rather than cyclical. So that which has a beginning has to come to an end, logically.

I also often suggest that societies that damage their landbase(s) are almost always those with eschatological beliefs, probably due to internalizing the recognition that their practices will lead to some sort of collapse.

200 years ago people did not have a good understanding of what created earthquakes, volcanic eruptions, tsunamis and so forth. And they did not know the age of the Earth. Today we are able to classify low frequency / high impact and high frequency / low impact events. A 10 mile comet hitting the Earth is extremely unlikely. And even this doesn’t mean it’s the end of the Earth. It might be the end of human beings and other species.

“What does this say about the psychological nature of humanity?”

That life and death is the foundation to everything. And, when left to ponder long enough, we get creative and imaginative.

Perhaps,
We are surrounded by death, as we are life. It is as real and present as night and day, light and dark. For every act of creation, there must exist an equal force dedicated to destruction. When we unlocked atomic power, we harnessed it for two overarching purposes: to generate energy to improve our lives, and bombs, to destroy those of others. So it goes, if the world was begun, so too it must end. This is at least reflective of the dualistic principles inherent in Eastern philosophy and its observations on the nature of human beings.

Humbly,

Sandman