I would say 'cultural' over 'racist'. Adults from the great depression developed habits of eating every last nibble, saving everywhere and anywhere, it was a mindset shaped by (traumatic) experience and subsequently passed down through generations despite such scarcity being overcome in America to the point where we have abundance and waste quite a bit of it. I can see the traces of that in myself, small but present, as raised by my parents, who were raised by the previous generation. Similarly, immigrants arriving from a brutal or very poor region will have a significant adjustment to western society - beyond the language barrier, but into how different groups of people regard one another and interact. Any white South African farmer coming to the US right now would likely be in fear of living in a mostly black neighborhood based on the trauma being carried out there compared to how outlandish such actions would seem here. They'd like struggle to understand police officers, black and white, working together and interacting with the public in the same manner as one another. Anyone's experiences, big or small, shapes who they are and how they see the world. Doesn't mean it is right or wrong, just different based on their life to that point. And, joining another culture/society inherently carries change, which brings fear.