What is the ecological fallacy?

The ecological fallacy refers to the erroneous assumption that trends observed at the group level automatically apply to individuals within that group. This fallacy occurs when researchers draw conclusions about individual behavior or characteristics based on aggregate data, which can lead to misleading inferences and misinterpretations. For example, if a study finds that a particular neighborhood has a high average income and, based on that, concludes that all individuals in that neighborhood are wealthy, this would be an ecological fallacy. Individual circumstances can vary significantly, and generalizing group data to individuals neglects the complexity and diversity within the group.

The other options address different types of reasoning errors or assumptions that do not capture the essence of the ecological fallacy. Believing every effect has a single cause is more related to oversimplification in causality. Making predictions based on insufficient data pertains to the lack of an adequate data foundation for sound conclusions. Ignoring external factors in analysis refers to overlooking variables that may affect the outcomes but does not specifically address the individual versus group data misinterpretation that defines the ecological fallacy.