Remember Gina Rinehart, the Australian billionaire who was recently called the richest woman in the world? Before that, she was mostly in the news for disparaging her children.

In a battle over the family trust, Ms. Rinehart said the kids “lacked the requisite capacity or skill, knowledge, experience, judgment or responsible work ethic” to manage the business and inheritance.

It turns out, it’s not just mining billionaires who doubt their kids’ money skills. A new study from U.S. Trust says that only half of millionaire baby boomers think it’s important to leave money to their kids. A third of them said they would rather leave the money to charity rather than their kids.

There are two explanations for their stinginess.

The kind explanation is that today’s boomers want their kids to grow up with the same middle-class values they had. They want their offspring to learn struggle and hard work and failure and the joys of earned success and all the other lessons that helped the boomers become successful (those, along with 30 years of bull markets and strong economic growth).

As Warren Buffett said, he wants leave his kids enough to do anything they want, but not so much that they can do nothing.

Aligned with this benevolent explanation is their commitment to charity and the broader world.

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