More than half of millionaire investors have not introduced their financial advisors to their his families, but the reasons for not doing so vary, says a new study.

Forty-one percent of millionaire investors who use financial advisors have introduced their children or other family member to their financial advisor, according to a new study published earlier this month by the Chicago-based Spectrem Group.

Millionaire investors cite various reasons for setting up an advisor-family introductory meet-and greet, according to the study. Thirty-eight percent of millionaire investors did it "to make a personal introduction." Another 18 percent said they did it to inform their children about their estate. Eleven percent said they wanted to educate their children about their investment portfolio and 5 percent wanted to discuss transferring control over their accounts.

What about investors who have not introduced their advisors to family members? Many of them just haven't gotten around to it, with 26 percent of millionaire households indicating that they plan to make this introduction in the future, according to the study.

Another 19 percent of advisors indicated that their client's children have no interest in their financial affairs; 10 percent indicated that their client's children are too young to discuss financial matters. Nine percent of millionaire households don't make the introduction because they don't want their family to know about their money, and 5 percent indicate that their family members are not responsible.

While a millionaire's decision on whether to introduce a financial advisor to family may be a highly personal and complicated decision, it's not so for an advisor, since most aren't doing the asking, according to Spectrem. Eighty-three percent of investors who work with a financial advisor indicated that their advisor has never asked to meet with their children or family.

-Jim McConville