Who a donor knows weighs heavily in philanthropic decisions, according to a survey of the 100 members of the Tiger 21 investment learning group. The members, whose aggregate investable assets total more than $6.5 billion, said they donated as much as 2 percent of their assets to charity.

The survey, conducted in July and released earlier this month, shows that 61 percent of the members made their donation decisions based primarily on personal connections. Only 3 percent said they regarded disasters or human tragedy as key factors in making donations, and 8 percent said they would consider donations based on written appeals.

Educational organizations were the big beneficiaries of the members' largesse; religious charities were a distant second, followed by the arts and civic causes. Tied for fourth were social service groups, political candidates and organizations, and science and medical institutions.

"Philanthropy is a highly individual decision," said Tiger 21 President Tommy Gallagher. "It not only reflects a person's values, but is formed by personal history, family experience, religious and ethic affiliation, and the charitable work of colleagues, friends and family."  

Charity wasn't limited to money. Half the group gave other types of gifts, and nearly three-quarters, 74 percent, also volunteer their time, at an average of 13 hours a month.

Tiger 21, founded in New York and now spreading to California and Florida, is a peer-to-peer learning group for affluent investors.