This study tried to control for all the confounding factors, so it looked at children who were equally intelligent and from the same social-class background, so it seemed as if it was the reading which really helped those children go on and score better on those school tests later in their lives.
Diese Studie kontrollierte alle störenden Faktoren und untersuchte Kinder mit ähnlicher Intelligenz und aus gleicher sozialer Schicht. Scheinbar half das Lesen diesen Kindern bei Tests in der Schule und im  Leben besser abzuschneiden.