The author asks What is the secret sauce that holds families together.
The research was done in 2001 with a 48-family sample...not exactly a large sample, but the results are interesting.
The Do-You-Know scale that he mentions in the article can be found here. My score is 16/20, but the questions are pretty vague asking for "some" information that you might know about specific times in your parents' lives. I guess "some" means more than one thing. Example:
What's your "Do-You-Know" score?