There is an implied causality in this article. Being rich -> Lose empathy.
I'd be curious to know if there indeed is causality in either direction (Less empathetic people get richer) or is it just correlation masquerading as causality.
You can find elsewhere an study about how psycopaths are usually found in leading positions, like politicians (specially in 3rd world, where salaries are high) and CEOs, amongst others.
If there was a limited amount of a certain resource, i would certainly have to own more than the next person in order to acquire that resource.