RESEARCHERS for the Kauffman Foundation surveyed more than 500 founders of successful businesses in high-growth industries to see what they had in common. These are some attributes that stood out:

* The successful entrepreneur's average age was 40.

* Nearly 70 percent were married when they started their company, and nearly 60 percent had at least one child.

* More than 90 percent grew up in middle-class or upper-lower-class families.

* Their average birth order was second in the family. Average number of siblings was three.

* They did okay in college, but weren't necessarily the cream of the crop. While 67 percent were in the top 30 percent of their class, only 37 percent were in the top 10 percent.

* Nearly two-thirds said that they'd always wanted to own their own company

* A solid 60 percent said that they were motivated to be their own boss because working for others didn't appeal to them.

* Just over half - 51 percent - were the first in their family to start a business.

* Only 11 percent of the first-time entrepreneurs received venture capital, while 9 percent got money from private or angel investors.