Referred to as INEFFECTIVE stereotyping. Everyone stereotypes as is part of human nature and which has evolved into part of our natural psychological defense mechanisms. The distinction is whether you're effectively stereotyping or ineffectively.lumping oc'rs into a broad category near marginal reprobates.
If you hold a stereotype against someone, that is fine as long as when they present new data to you which would be contradictory to that you no longer hold them in that category. To effectively stereotype means to be constantly evaluating new data on the topic/subject so that you address it and issues appropriately. If you choose to ignore the new data and still hold the original stereotype against someone, then you are ineffectively stereotyping and it the skill will serve you no good.