Describe the four causes of imperialism

I don't think there are "the" 4 causes, as in 4 causes widely agreed to be the most important: there were many more causes. But here are 4 causes that I find important:

-political importance and prestige: countries wanted to be better than other countries ...

-economical: countries sought wealth, for example natural resouces

-religious: countries sought favors with the pope by converting the "pagans"

- curiousity in the Age of Exploration: the will to discover our planet