Societal Stratification by Marriage

"Marriage is both a cause and consequence of economic, cultural, and psychological stratification in American society."

What are the implications of this statement? I find it interesting that marriage is a consequence of stratification. Meaning what, exactly? That an individual is prompted to marry in order to economically stabilize? To "marry up" and climb the social ladder? Or maybe couples affect the economic climate due to joint incomes, creating a new kind of class.

What of the "cause of . . . psychological stratification"? Perhaps this is in reference to the way offspring are nurtured (or not) and, say, in reference to the effects of divorce on children. This brings into consideration the argument of nature vs. nurture when speaking of a child's (or individual's) psychological wellbeing; in this case, it sounds like nurture is the active party.

And cultural stratification . . . I can only guess as to what this may mean. Maybe an example is an interracial couple, bringing together different cultural traditions and ways of life. Their union creates a blended culture all its own.

Maybe I'm way off base on all of these. They are just my thoughts an interpretations. At any rate, it's a provocative quote. Any thoughts?