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.
Ovo je istraživanje pokušavalo kontrolirati sve konfliktne faktore, pa je pratilo djecu koja su bila jednako inteligentna i koja su dolazila iz iste društvene klase, pa se ispostavilo da je upravo čitanje pomoglo toj djeci da postižu bolji uspjeh na testovima,  a kasnije i u životu.