The inverse relationship between extension and intension does not hold for concepts in general.

Evidence

In summary, the claim about the inverse relationship between extension and intension does not hold for concepts in general. In fact, for the family resemblance school of concepts there can be a positive relationship between intension and extension. — Gary Goertz, Social Science Concepts, 499

Categorization

• SEED: The counterintuitive core finding — the extension/intension tradeoff is school-specific, not a universal law. Worth its own treatment.
• XREF: Connects to Sartori’s ladder of generality and to any prior chapter claim that concept intension trades off against extension.