you are (or the authors of the study you mentioned) are confusing cause and effect.
think about it.
I could line the walls of a room with 1 million books from birth and it wouldn’t make a group of retarded children smart.
The real truth is that smart people are more likely to own books, and when those smart people have children, those children are more likely to be smart like their parents. The presence of the books wasn’t what was important.
I am guessing that smart people probably make their beds more often than dumb people. Would you believe the results of a study that shows that children that live in homes with their beds made are on average more intelligent? Would you then start encouraging dumb parents to start making their beds to increase the intelligence of their children?
The authors of the study said, "the intellectual environment those volumes reflect — gives children an enormous advantage in school."
It's well known that intellectual enrichment is a strong factor in childrens' neurological development.
I would believe a do-gooder such as Michelle Obama starting a campaign to get people to make their beds for that reason.