Schneier&#x27;s point is not only that those attributes should be <i>ignored</i>, but there should be <i>no correlation</i> between those attributes and the end result of the algorithm.  You can quite easily find examples of algorithms which do not include race or gender as an input, yet have a disparate impact.  Schneier is saying that algorithms with disparate impact should be avoided without regard to procedural fairness, proportionality of outcome, or correctness.