The door to the subway train slides open, revealing three tall, young black men, crowding the entrance, with hooded sweatshirts pulled up over downward-turned faces; boxer shorts billowing out of over-large, low-slung jeans; and sneakers with the laces untied.

Your response to the look — and to this trio on the subway — depends in part on the context, like the time of day, but especially on how you feel about young, male blackness.

If it unsettles you — as it does many people — you never get beyond the first impression. But those of us who are not reflexively uncomfortable with blackness can discern the clues that tell who these kids are. They may be tall, but their hormonally pockmarked faces, narrow hips and the cartoon-patterned underwear show that they are probably 15 years old, at most. The grimy black book bags, barely visible against the black hoodies, make them students on the way to school.

Young black men know that in far too many settings they will be seen not as individuals, but as the “other,” and given no benefit of the doubt. By the time they have grown into adult bodies — even though they are still children — they are well versed in the experience of being treated as criminals until proved otherwise by cops who stop and search them and eyed warily by nighttime pedestrians who cower on the sidewalks.