Just because something is genetically based, and we're therefore predisposed to it, doesn't mean that we'll necessarily behave that way. Much simpler animals, such as insects, are more hard-coded in that regard, but in humans we can override our genetically coded innate instincts with learned behaviors - generally a useful and powerful capability, but one that can also lead to all sorts of disfunctional behavior based on personal history including things like brainwashing.