Having been adopted at the age of three and having lived for a very long time, I found this article and discussion very interesting. But I think there are more things that need to be considered, such as generational issues, the part of the country where you were raised and the sign under which you were born.
My adoptive parents were staunch Democrats - but the old style - and voted Democrat until they died several years ago. I don’t remember that politics was ever discussed much in our family when I was growing up. As an adult, it only caused strife so I quit talking about it. Raised as a Southern Baptist in a very hard working family. I have retained their strong value system throughout my life as it relates to church, work, education and how my children were raised but have always voted Republican. However, I do espouse opinions and, according to my adoptive mother, did engage in activities which she called “falling off the wagon” that looking back absolutely had to be the result of genes, my birth sign or generational changes in attitudes.
It's always interesting to meet people who seemingly out of the blue develop personality traits that don't fit until you find out something about their ancestors or real parents.
By the way, I assume that by "old school" Democrats you mean FDR/Truman Democrats, or anti-FDR southern Democrats? That's a completely different bird from today's Democratic party!