Given the column names, it appears they're based on published studies. Presumably each publication has its own methodology.
For instance it looks like "Becker 2019" is this book ( https://richardlynn.net/wp-content/uploads/2024/08/THE-INTEL... ) called "The Intelligence of Nations". This in turn is based on the "National IQ Dataset" ( https://viewoniq.org/?page_id=9 ) which appears itself to be an aggregation of data from numerous other publications. (The data file has a "Ref" spreadsheet with 414 citations.)
I'm reflexively skeptical of documents that seem to suggest this level of comprehensiveness, leaving aside the issue of whether IQ is a measure that is validly comparable across all nations.
What test(s) were used to get these values? How were the subjects selected?
For instance it looks like "Becker 2019" is this book ( https://richardlynn.net/wp-content/uploads/2024/08/THE-INTEL... ) called "The Intelligence of Nations". This in turn is based on the "National IQ Dataset" ( https://viewoniq.org/?page_id=9 ) which appears itself to be an aggregation of data from numerous other publications. (The data file has a "Ref" spreadsheet with 414 citations.)
I'm reflexively skeptical of documents that seem to suggest this level of comprehensiveness, leaving aside the issue of whether IQ is a measure that is validly comparable across all nations.