Well, maybe I misinterpreted what the author meant. In fact, I was a bit casual myself: statistical bias, which is what I meant, would have been more accurate t

Well, maybe I misinterpreted what the author meant. In fact, I was a bit casual myself: statistical bias, which is what I meant, would have been more accurate than what I wrote, machine learning bias (which might be interpreted as the bias in "bias and variance", which has nothing to do with the discussion). The thing is, if the training data was generated by human behaviour, warts and all, then it is going to represent our prejudices. If this is a concern, then it seems to me that ML might not be the right technology to make decisions that have a political dimension. If we want the system's predictions to be PC, then a rules based system might be more appropriate, blast from the past, unless we start labeling samples, with their output as an extra feature, as "PC" and "Not PC".