Faulty Generalization

Faulty Generalization is an informal logical fallacy in which a conclusion about an entire group or category is drawn from evidence that is insufficient, biased, or unrepresentative. This fallacy undermines sound reasoning by leaping from limited observations to sweeping claims that the evidence cannot adequately support.

This fallacy serves as an umbrella category for several related errors in reasoning, including hasty generalization (drawing conclusions from too few examples), sweeping generalization (applying a general rule to all cases without acknowledging exceptions), and biased sampling (drawing conclusions from a non-representative group). What unites these errors is the failure to ensure that the evidence properly supports the scope of the conclusion.

Faulty generalizations are particularly common in everyday reasoning because humans naturally look for patterns and tend to form broad conclusions quickly. While this mental shortcut can be useful, it becomes fallacious when the sample size is too small, when the sample is not randomly selected, or when important differences between cases are ignored. Recognizing this fallacy requires evaluating whether the evidence presented truly represents the larger group being discussed.

To avoid committing this fallacy, one should consider whether the sample is large enough, whether it was selected without bias, and whether there might be significant exceptions to the proposed generalization. Sound reasoning requires that the breadth of a conclusion match the strength and scope of the supporting evidence.