Participants
A total of 567 sixth and seventh graders from eight Danish state schools
participated in the study by filling out a questionnaire at both T1 and T2
(Mage = 12.6 years at T1, 52% boys). The inclusion criteria of the study were
state schools because the majority of Danish children go to these schools.
The participants were recruited from schools in a medium-large town centrally
situated in a Danish municipality. Half of the schools were located in
the town center and the other half in suburbs outside the center. According
to headmasters and teachers, the majority of the children attending these
schools came from average middle class families, although some children
also attended the schools from higher-middle class and lower-middle class
families.