We see the world by applying the expectations generated by the statistical lens of our own past experience, and not (mostly) by applying the more delicately rose-nuanced lenses of our political and social aspirations. So if the world that tunes those expectations is sexist or racist, future perceptions will also be similarly sculpted — a royal recipe for tainted evidence and self-fulfilling negative prophecies. That means we should probably be very careful about the shape of the worlds to which we expose ourselves, and our children.