Stereotypes lose their power when the world is found to be more complex than the stereotype would suggest. When we learn that individuals do not fit the group stereotype, then it begins to fall apart.

Koch’s remark frames stereotypes as cognitively convenient but fragile shortcuts: they persist only so long as people lack counterevidence. Once real experience reveals that human lives are messier than a single label—and, crucially, that individuals routinely contradict what is “supposed” to be true of their group—the stereotype’s explanatory force weakens. The quote also implies a practical ethic: contact, attention, and curiosity are antidotes to prejudice because they replace abstract categories with particular persons. In this view, social progress depends less on arguing about groups in the abstract than on widening the range of encounters that make simplistic generalizations untenable.