That makes sense. Because the same qualities that lead to higher incomes are required to care about things around you. For example, building skills and wealth

That makes sense. Because the same qualities that lead to higher incomes are required to care about things around you. For example, building skills and wealth take a long term view and the ability to make sacrifices, deferring enjoyment now for the possibility of future enjoyment. And a tree takes short term sacrifice of time for something that will have take years to materialize.