Averaging components can make the whole weaker than its strongest part.

Evidence

The substantive logic is that, for example, multiple alliance commitments are stronger than one alliance commitment. If one were to take the mean then one would have the counterintuitive result that the overall alliance commitment is less than the strongest one. — Gary Goertz, Social Science Concepts and Measurement, 983

Categorization

• DEFINE: Explains why the mean is not a plausible rule for additive concepts: a part cannot exceed the aggregate.