Marks (2010) hypothesized that IQ differences across time, race and nationality are all caused by differences in literacy because intelligence test performance requires literacy skills not present in all people to the same extent.
Intelligence test performance requires literacy skills not present in all people to the same extent. Marks (2010) hypothesizes that IQ differences across time, race and nationality are all caused by differences in literacy.
Marks (2010) hypothesizes that IQ differences across time, race and nationality are all caused by differences in literacy. Intelligence test performance requires literacy skills not present in all people to the same extent.
Marks (2010) hypothesizes that IQ differences across time, race and nationality are all caused by differences in literacy. Intelligence test performance requires literacy skills not present in all people to the same extent.