All  young  men  in  Norway
must  take  a  test  of  their  cognitive  ability  at  age  nineteen
in  preparation  for  required  military  service.
This  is  commonly  called  an  IQ,or  intelligence  quotient  test
The  researchers  compared  the  test  results  of  one  hundred  seven  thousand  young  men
to  their  years  of  school.
Taryn  Ann  Galloway  is  a  researcher  at  the  University  of  Oslo.
TARYN  ANN  GALLOWAY:
"The  young  men  who  were  basically  forced  to  stay  in  school
for  two  years  longer  actually  did  have  higher  IQs.
So,based  on  that,
we  were  able  to  say  that  increasing  compulsory  schooling
did  actually  have  an  effect  on  their  cognitive  abilities  as  measured  at  nineteen  years  of  age."