I do not think anything in the essay is surprising. There can be no doubt that in absence of other information, everybody uses whatever is immediately discernib

I do not think anything in the essay is surprising. There can be no doubt that in absence of other information, everybody uses whatever is immediately discernible, such as race, age, gender, attire, height, athleticism, beauty, etc, to modulate behavior. A sane individual will improve the accuracy of the initial rough assessment as more information becomes available. What else could anyone be reasonably expected to do? Ignore whatever they learned about the world and treat every individual exactly the same regardless of their outside characteristics as if these outside characteristics gave absolutely no clue about what kind of behavior is appropriate ? That seems impossibly stupid.