I'm a Democrat. My brother's a Republican.
I'm a progressive. My brother's a conservative.
Clearly, we see the the world VERY differently. Given the fact that we're 12 years apart, could the differences in our politics come from changes in Mom & Dad's parenting skills in the intervening decade? After all, he spent his formative years as an Army brat born in Texas, while I was the child of a bus driver and a state bureaucrat born in the working class suburbs of Baltimore.
This article seems tho think so.