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.
Este estudo tentou controlar todos os fatores contraditórios. Então ele observou crianças igualmente inteligentes e com mesmo histórico social-escolar, e parece que a leitura foi o que de fato ajudou as crianças a pontuarem melhor nos testes escolares posteriores na vida.