Nearly two-thirds of affluent Americans believe the next generation should be responsible for creating its own wealth, but only 30 percent have included instructions in their wills that would hold their heirs accountable, according to a survey released May 14 by Pittsburgh-based PNC Wealth Management. "When it comes to leaving a legacy, too few individuals are taking the steps to ensure their heirs do not have unfettered access to their money," said Martyn Babitz, senior vice president of PNC Wealth Management and a senior trust advisor for Hawthorn, which serves ultrahigh-net-worth families.

Those trusts that do require milestones generally include age or a college education among the requirements. According to the survey, younger individuals were more likely to attach strings to their estates: 56 percent of those ages 18 to 44 said they have stipulations, while only 19 percent of those over the age of 65 have.

The poll, conducted last fall, included 1,123 adults with incomes of at least $150,000 and investable assets of at least $500,000.