The wealthy have trust funds, investments, and businesses since money enables the narcissist to be who he truly is and use money to control and manipulate people.

For this reason, it has long been a trait that only the wealthy can afford to have since if you were poor a century ago and thought of to be ill tempered among your peers and difficult to get on with, that would lead to that person being ostracized from society, singled out and labelled.

As a consequence word would get around and they would not be hired, married, or have any friends diminishing their chances of survivability greatly.