Super-rich families — those with hundreds of millions, even billions of dollars — are almost as likely to lose all or most of their wealth within a couple of generations as they are to amass a fortune in the first place. That’s why families in this bracket, and some families that aspire to join them, put a lot of effort into fostering family cohesion and coming up with ways to pass assets to the next generation with as little friction — in the form of taxes, squabbles and bad management — as possible.

The thinking is, a family that gets along, has a more or less common vision and has a healthy sense of the privileges and responsibilities of great wealth is less likely to divide and squander its money. In aid of these concepts, some ultra-wealthy families are going in for videotaped “ethical wills,” according to Wealth-X.

Setting aside Wealth-X’s claim that this device — a staple of film and television scripts for the last half century at least — is an innovation, the website is probably right to say that some filmed ethical wills “can help create a bond throughout a family and help to ensure that assets are not disputed” by appealing to survivors’ emotions in ways and on levels that few legal documents can rival.

Though such films, however well made, can’t take the place of sound planning, prudent investing and good parenting, they can help families preserve the values and life lessons of previous generations as examples to those who follow.