Country-based size is probably false
Alleged country-related differences in penis size e.g. in Europe do not make any logical sense and in my opinion are a result from different measurement methodologies applied and/or different recruitment / selection criteria.
As there was never a harmonized study with standardized methodology carried out across a broad spectrum of countries, alleged “national” differences are most likely purely statistical or methodological difference effects, which also gives you a hint that it is nonsense to believe in any “precise” average numbers.
