The Thomas theorem posits that if people define situations as real, they are real in their consequences. One classic example of this can be seen in the realm of social interactions and perceptions of crime.
Imagine a neighborhood that has a reputation for being unsafe. Residents and visitors may come to perceive the area as dangerous, even if crime rates are actually low. This perception leads to tangible consequences: people may avoid the neighborhood, businesses might struggle to attract customers, and local property values may decline.
In this case, the belief in the danger of the neighborhood is not necessarily based on objective facts, but rather on the interpretations and definitions that individuals and the community have made about it. The consequences of this collective belief—such as economic decline and social disengagement—are very real, showcasing the essence of the Thomas theorem.