Exception fallacy

Disciplines > Argument > Fallacies > Exception fallacy

Description | Discussion | Example | See also

Description

The exception fallacy occurs when data about an individual is used to draw conclusions about a group of people.

Example

A first class passenger on a train is arrogant and rude to a person who walks into the first class compartment. The person concludes that all first class passengers are arrogant.

Discussion

We are always in a hurry to classify people and groups and, when we have limited data about a group we will often use what information we have, even if it is not statistically valid -- and even if it is a single data point.

This data may be the exception rather than the rule - hence the name of the fallacy.

This effect is particularly common when several factors are taken into account:

A person is encountered who does not fit into current categories, for example where there is a dominant attribute for which there is no stereotype available.
Other attributes are available and can be evaluated.
Other people who have similar dominant attributes are not available to determine whether additional attributes correlate. Thus the evaluation cannot be disconfirmed.

This fallacy is an effective reversal of the Exception fallacy.

Classification

Deductive