Merrill Lynch surveyed 656 American adults with at least $3m in investable assets and found 48% have not discussed distribution of assets upon passing with family members.
Some 36% have talked about the transfer and 10% do not intend to discuss anything.
The survey also found there was an equal proportion of people who have and haven’t discussed (33%) assets already gifted during lifetime; such as assets held in a trust, funding education, a down payment on a first house or another purpose.
“Decisions about family money have the potential to change lives, yet the outcome depends on how well the purpose and reasoning behind those decisions are understood, and too often that is left unsaid,” said Stacy Allred, head of the Merrill Centre for Family Wealth.
“Misunderstanding can lead to family conflicts, resentment and other unintended consequences including the misuse or loss of family wealth.”
When asked what they consider to be the most important idea to communicate when discussing wealth with family, the top response was to be a good steward and handle family money wisely.
However, only 46% have talked with heirs about fundamental family values and operating principles.
On the distribution of their estate, 69% of wealth holders plan to divide their assets equally among heirs, while the rest said allocation decisions are based on specific criteria; such as merit for individual contributions (11%) or need (8%).
Some 22% will openly share details of their estate plan with the whole family, 17% would share information only as it applies to each person.
The survey also found three-quarters of participants, including more men (79%) than women (68%), report complete confidence in their financial decisions.
Looking back, however, just 56% of people said their decisions always turned out well.
The rest reported mixed results, including 21% who said all their decisions turned out badly or they delayed making decisions because they were unsure of the outcome.
Matthew Wesley, director of Merrill Centre for Family Wealth, said: “The best form of financial parenting and a big part of improving the outcome of decisions involves putting more care into the decision-making process itself.
“Family wealth decisions can be complicated by family dynamics, a long-time horizon and unrecognised biases that call for a deliberate and disciplined approach.”