A mistake based on believing that what is true for a group must also be true for each individual in the group.
The problem of inferring characteristics of individuals from aggregate data referring to a population; equivalently, the problem of inferring individual household characteristics using areal unit (spatial) data (Johnston et al. 1994; Wrigley et al. 1996).
The inference that a correlation between variables derived from data grouped in social or other aggregates (ecological units) will hold between persons (individual units).
Most often referred to as a logical flaw which results from making a causal inference about an individual phenomenon or process on the basis of observations on groups.
False conclusions made by assuming relationships found through research with groups can be attributed to individuals.
The mistake of assuming that where relationships are found among aggregate data, these relationships will also be found among individuals or households.
The fallacy one commits when making inferences about individuals from information about groups or aggregates (See Atomistic Fallacy).
The ecological fallacy is a widely recognised error in the interpretation of statistical data, whereby inferences about the nature of individuals are based solely upon aggregate statistics collected for the group to which those individuals belong. This fallacy assumes that all members of a group exhibit characteristics of the group at large. Stereotypes are one form of ecological fallacy.