The rich are different from you and me

They need human resource departments to get the boyfriends up to speed;

The onboarding process is one way wealthy families are trying to smooth intrafamily relations and safeguard their fortunes for future generations. As the scions of the patriarchs grow up and get married, the importance of teaching about wealth and its preservation rises, according to families and their advisers.

Where there are problems, there are opportunities;

The issue has taken on more prominence since the financial crisis, when families, shaken by market turmoil, began scrambling for ways they could work together to preserve their wealth. Charles Grace, a managing director of Family Office Exchange, a Chicago consulting and peer-networking group that has worked with more than 2,000 wealthy members, said that the crisis caused many families to formalize how they handle such issues in family mission statements or "family constitutions."

Some families have set up formal committees that help coordinate communication and financial education with new family members. "We're having this conversation all the time with families," Mr. Grace said. "The question of how you define your family is huge, and that includes the role of in-laws."

That, in turn, has created a growing cottage industry of wealth advisers who focus on family dynamics and other nonfinancial issues, such as inclusion for new family members, Mr. Grace said. The goal: to minimize conflict and prevent rifts from forming.

And allowances to be determined.