We're hardwired to mistrust "the other" but what exactly defines "the other" is 100% learned behavior. Humans are, by nature, tribal. Our definition of tribe expands the more calm and smoothly everything works. At this exact moment in history, we are just barely capable of identifying our country generally as "our tribe". But in times of conflict or strife that circle shrinks. In the immediate aftermath of a natural disaster, your tribe is pretty much limited to physically nearby blood relatives (and spouses) and everyone else is a threat.
In earlier days in the United States there was rampant discrimination and racism against the Chinese, the Italians, the Irish, and others. We still have some issues with racism towards Asian Americans (that can *partly* be traced back to World War II) but you'd be hard pressed to find rampant discrimination against the Irish and Italians anymore.
TLDR: the definition of "other" is learned, not innate.