I think they are very typical, what this study and others say. Big studies into language and parenting, shocking percentages (that I can't remember and don't have to hand) where parents don't think you need to talk to babies, think language acquisition can happen through exposure tv, know no nursery rhymes etc.
Didn't mean to imply that these parents don't do these things at all, that gives real brain atrophy...think scans of Romanian toddlers. Tiny shrunken brain especially in regions that deal with emotion. Lots of parents don't do these things enough, aren't consistent, aren't skilled at parenting.
This study says what others have, what primary heads bang on about at conferences. What those dealing with adoption know well, bugger up the first few years and the rest are proportionally disadvantaged.
Most children will find high schools don't address literacy, they focus on making the curriculum accessible. There are schools that have withdrawn the illiterate from the curriculum and focused on reading recovery but few do this. Ther are horrific cost implications when these chidren usually attract no extra funding.
Are we the worst? No idea, we invest less in 0-3s than scandanavian countries, have more americanisation than lots of Europe. We have some places socially more than economically deprived, we have too much wealth inequality...all contributes.