Are the two able to be separated? Does white culture = white race? Or can one be white and not be a part of white culture? Can this be applied to all races? Or just some, or one? And how does this apply to how a race and/or culture acts/is?
A few meme examples for that last part: "Whites are racist." "Blacks are violent." "Jews are greedy."
Can a race/culture be talked about without being a racist/bigot even if when talking about an aspect of that race/culture negatively.
Stereotypes often have a certain amount of truth at their core, as relates to broad generalizations, but individuals and real life tend to get more complex than can be thus explained.
As BrewerBob said, there is more than just one white culture, or one black culture. There are cultural distinctions between countrified and citified whites and blacks, between upper-middle-class professionals and blue collar workers, between academics and the general populace... and the generational uber-rich are a class unto themselves to some degree.
I've found that I get along well with and have much in common with most country-fied and/or working-class black folks. One of my good work-buddies referred to himself as a "black redneck" and he was... a hunting and fishing and beer-drinking "good ol' boy" who was more at home in the woods than the "hood".
I've been in the home of an upper class black family (Mr was a surgeon and Mrs was a college professor), and they were as politely genteel and aristocratic as any old-money Southern blue-blood with plantations in their family tree, and would have fit in with the country club crowd better than I could on my best day.
South vs North, East vs West, also cultural differences that transcend race to some degree.
Yet it isn't all about economic class or education or upbringing or environment. There are things specific to each race (or ethnic group, the two terms are often hard to entirely separate) which we DON'T share. My ancestors don't have a history of being enslaved within recent centuries, or treated as second class citizens until recent generations. Many blacks may not feel as connected to the founding of the country as their ancestors mostly didn't come here willingly. Etc.
Even so, when it comes to first impressions, most of us are more readily attracted to those who look like us than those who look different, at least when that is all we know about someone.